JPH08150713A - Ink jet recording apparatus and detection of non-emission thereof - Google Patents

Abstract

PURPOSE: To conduct detection without lowering throughput even when the flow velocity of heat is high by detecting the flow velocity of heat from the vicinity of heating elements or the part having the heating elements incorporated therein to other member or air at the time of the detection of non-emission or prior to detection and altering the detection condition of non-emission on the basis of the detection data. CONSTITUTION: The temp. change of a recording head during the period from the completion of printing to the start of emission for detecting non-emission is measured to detect the flow velocity of heat from a heater board to the other member constituting the recording head or air. In measurement, a diode sensor 20C is arranged on the heater board 20G of the recording head. The heat characteristic of an emission heater is compared with a judging threshold value determined by the value showing the flow velocity of heat to judge the non-emission of the recording head. By changing the threshold value for judging non-emission on the basis of the flow velocity of heat, the detection of the non-emission of the recording head is enabled. A long standby time before the detection of non-emission is dispensed with.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus capable of detecting non-ejection of ink and a non-ejection detecting method of the apparatus. Here, recording includes printing (printing) of ink onto all ink supports such as cloth, thread, paper, and sheet material that receive ink. A printer as an output device is included, and the present invention can be applied to these.

[0002]

2. Description of the Related Art In a recording head of an ink jet recording apparatus, when the ink is left for a long time without being ejected, the ink is thickened particularly in an ink liquid passage near an ejection port, and normal ejection is performed. It may disappear. Further, when the ejection is continuously performed when recording is performed with a relatively high print duty, fine bubbles are generated in the ink in the liquid passage due to the ejection, which grows and grows. Air bubbles may remain in the liquid passage and affect ejection, and similarly, normal ejection may not be performed. In addition to the air bubbles that accompany the ejection as described above, there are air bubbles that are mixed in the ink in the ink supply system such as the connection portion of the ink supply path.

Not only does the reliability of the recording apparatus deteriorate due to the above-described non-ejection of ink, but when high-duty printing is performed with the recording head in a state where the recording head cannot eject normally, the state of the recording head is far more than normal. In some cases, the temperature rises to a very high temperature, the recording head itself is damaged, and the durability is impaired.

In the conventional ink jet recording apparatus, for example, for the ejection failure due to various causes, for example,
(I) Capping processing for covering the ejection opening surface of the recording head to prevent thickening of ink when ejection is not performed,
i) Ink suction processing that sucks ink from the discharge port to discharge the thickened ink in this capping state, and (iii) Ink the prescribed ink receiver, which is composed of the ink absorber, etc., as in normal recording. A discharge recovery process such as a blank discharge process for discharging and similarly discharging the thickened ink is performed.

Among the above processes, the discharge recovery process (iii) is automatically performed at predetermined time intervals, for example, when the apparatus is turned on or during the recording operation, or when the user needs it. This was done by pressing the recovery button or the like.

However, in an ink jet recording apparatus which performs ejection recovery processing in conjunction with power-on of the apparatus, the number of times of ejection recovery processing is unnecessarily increased when used by a user who repeatedly turns on and off the power supply. However, there is a problem that the amount of ink consumed and the amount of waste ink sucked from the ejection port increase. On the other hand, in the ink jet recording apparatus in which the user operates the recovery button according to the judgment to perform the recovery process, the user actually prints whether the recording head is in a normal state or a non-ejection state. Unless it is understood by the user, there is a problem in that the operational clarity is lacking.

In order to solve this problem, a technique for judging whether or not the print head is not ejected according to a temperature rise in the print head caused by the idle discharge and a temperature drop in the print head after the idle discharge (Japanese Patent Laid-Open No. Hei 4- No. 133749), or a technique for determining whether or not the print head is not ejected according to a temperature rise in the print head caused by the idle discharge and a temperature drop in the print head after the idle discharge (Japanese Patent Laid-Open No. 5-293968).
No.) is disclosed. Comparing the case where the print head is in the normal ejection state and the case where it is in the non-ejection state, when the ejection state is normal, part of the heat generated by the idle ejection is transferred to the ink, and part of it Is used to cause the film to boil the ink, and part of it goes out of the recording head together with the ink droplets. On the other hand, when the recording head is in the non-ejection state, the temperature difference of the temperature rise and the temperature difference of the temperature decrease are larger than those when the ejection is favorably performed. Therefore, for example, when the temperature change between the temperature increase and the temperature decrease (for example, the sum thereof) exceeds a predetermined value, it can be determined that ejection failure has occurred in the print head.

Further, the temperature rise characteristic of the recording head is measured in advance, and the condition of non-ejection detection is changed to improve the accuracy of non-ejection detection, and the recording having variations in heat generation characteristics and heat radiation characteristics. A technique for detecting non-ejection of a head (Japanese Patent Laid-Open No. 5-309832) is disclosed.

Further, by measuring the heat generation characteristics and heat radiation characteristics of the recording head in advance and changing the conditions for detection of non-ejection, the non-ejection detection of the print head having variations in heat generation characteristics and heat radiation characteristics can be performed. The applicant of the present invention has proposed a technique (Japanese Patent Application No. 5-206689) for protecting the recording head by improving the accuracy and controlling the energy applied to the recording head to detect ejection failure.

[0010]

However, it has been found that the above-mentioned conventional improved technique also has the following drawbacks. When the non-ejection detection is performed immediately after the high-duty printing is continued for a long time, the temperature rise of the recording head due to the idle ejection is small, and the non-ejection may not be detected.

FIG. 18 is a schematic diagram for explaining the phenomenon. The line segment (a) in the figure shows the temperature rise / decrease of the recording head when a certain number of times of driving is performed in a room temperature environment. The line segment (b) is the result of measuring the temperature rise / decrease of the print head by driving the print head a fixed number of times in the same manner as in the line segment (a) immediately after the print head was rapidly heated by driving. Is shown. As shown in the figure, in comparison with the result of (a), in (b), the temperature change of the temperature increase / decrease is small.

The ink jet recording apparatus that carried out this measurement has the same structure as that used in the first embodiment of the present invention described later, and the structure will be described in detail in the first embodiment. Then, only the main points will be described.

This recording head is provided with a heating element, and thermal energy generated from the heating element causes bubbles to be generated in the ink, and the growth of the bubbles causes the ink to be ejected from the nozzles of the recording head. The structure of this recording head is shown in FIG. As shown in the figure, a heater board 20G provided with an electrothermal conversion pair (heating element) is adhered to an aluminum board 21 via an adhesive layer 22, and these are collectively referred to as a print head 1A. further,
The recording head 1 shown in FIGS. 4 and 5 is provided with four of the print heads therein, and the electrodes of the recording head 1 are connected to the respective print heads, and the ink tank 2
Ink is supplied to the print head from. In addition to the print head, the recording head 1 is made of a polysulfone frame with electrodes. The print head fixed in the frame is in contact with the air in the frame in most of the area other than the connection between the electrodes and the ink tank. The frame is not sealed, but there are no large gaps in which air can enter and leave.

The mechanism considered to be the cause of the phenomenon shown in FIG. 18 will be described with reference to FIGS. 19A and 19B based on the structure of the recording head. FIG.
(A) and (b) have shown the distribution of the heat energy of the said heater board 20G, the aluminum board 21, and the air in the said frame (it is hereafter called air for convenience of description). The vertical axis represents temperature. Horizontal axis is heater board 20G
The heat capacities (indicated by HB in the figure), the aluminum board 21 (indicated by BP in the figure) and the air (indicated by air in the figure) are shown, and the vertical axis indicates the temperature. Solid arrows indicate the transfer of heat energy from the heater board 20G to the aluminum board 21 (hereinafter,
Called heat transfer). The chain line arrow indicates the transfer of heat energy from the aluminum board 21 to the air (hereinafter referred to as heat transfer). The heat transfer of the former is relatively faster than that of the latter because the heat is transferred through the thin adhesive layer 22. In the figure, the white block portion shows the distribution of thermal energy at the start of driving the recording head in the above measurement. The shaded block portion shows the distribution of thermal energy after the recording head is driven a certain number of times.

The mechanism of the phenomenon shown in FIG. 18 will be described below with reference to FIG. Note that FIG. 19 is made by exaggerating the respective temperature differences for ease of the following description.

The white block in the graph (a) is
As described above, the state of the distribution of thermal energy at the time of starting the recording head drive in the room temperature environment is shown. The heater board 20G, the aluminum board 21, and the air have almost the same temperature. In this case, the heat energy generated by driving the heating element is transferred to the aluminum board and the air according to the heat transfer and the speed of the heat transfer.

The white block in the graph (b) is
The state in which the temperature is raised by driving the recording head is shown.
Heater board 20 because heat transfer is faster than heat transfer
The temperature difference between G and the aluminum board 21 is relatively small. From this state, a fixed number of recording heads are driven. Compared to the case of (a), aluminum board 2 in (b)
Since the temperature difference between No. 1 and the air is large, the heat transfer becomes faster, and the heat energy of the aluminum board 21 moves to the air. Along with this, heat transfer during the drive of the print head (indicated by a solid arrow in the figure) becomes faster, and as a result, the temperature of the heater board 21 is raised by a constant number of drives performed after the drive of the print head is raised. The degree will be small.

To summarize this phenomenon, the aluminum board 21
From the above to the air, in other words,
Corresponding to the temperature difference between the aluminum board 21 and the air,
The heat flow rate from the heater board 20G to the aluminum board 21 changes. That is, the high-temperature thermal time constant changes due to the outflow of heat generated in the heater board 20G.

That is, when the temperature near the heating element or the member in which the heating element is built becomes high due to long-duration high-duty printing, and the temperature gradient is large, the speed at which heat is transferred (hereinafter referred to as heat flow velocity). ) Becomes faster, and the phenomenon in which the degree of temperature rise due to idle discharge becomes smaller as described above occurs.

Due to this phenomenon, in a recording head having a large number of nozzles, ejection failure may not be detected when driving at a high frequency. Further, even when the high-duty driving is performed in a state where the ink is not supplied to the recording head, the non-ejection may not be detected in some cases.

As a countermeasure against this phenomenon, it is conceivable to provide a waiting time of a fixed time before performing the idle discharge for detecting the non-discharge. In fact, this method allows the non-ejection detection to be performed after the temperature gradient becomes somewhat small. However, when high-duty printing is performed for a long time, the temperature gradient may not become sufficiently small in the waiting time of several seconds. In addition, the provision of the waiting time leads to a decrease in the throughput of the recording time, which deteriorates the performance of the recording apparatus.

It is an object of the present invention to solve these problems and to make it possible to detect non-ejection of the recording head without lowering the throughput of the recording apparatus even when the heat flow velocity is high.

[0023]

According to the present invention, prior to detection of non-ejection, the heat flow velocity from the vicinity of the heat generating element or the member having the heat generating element to another member to which heat is transmitted or to the air is detected or estimated. Then, the condition for non-ejection detection is changed according to the information, and thereby the above-mentioned problem is achieved.

That is, in the ink jet recording apparatus according to the first aspect of the present invention, when the non-ejection is detected or prior to the non-ejection detection, another member to which heat is transmitted in the vicinity of the heat-generating element or from the member having the heat-generating element incorporated therein, or The present invention is characterized by having a correction means for detecting or estimating the heat flow velocity to the air and changing the condition of non-ejection detection according to the information.

In the ink jet recording apparatus according to the second aspect of the present invention, the correction means detects the heat flow velocity based on at least the temperature change of the recording head temperature immediately before the ejection failure detection.

In the ink jet recording apparatus according to a third aspect of the present invention, the correction means estimates the heat flow velocity at least at the time of non-ejection detection or immediately before non-ejection detection and the environment in which the printing apparatus is placed. It is characterized in that it is performed based on the difference from the temperature of.

In the ink jet recording apparatus according to the fourth aspect of the present invention, the correction means detects the heat flow velocity at least at the time of the non-ejection detection or immediately before the non-ejection detection, the temperature of the member in which the heating element is formed, and the heat from the member. It is characterized in that it is performed based on the difference with the temperature of other members through which the heat is transmitted.

According to a fifth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to fourth aspects, based on the detected or estimated heat flow rate information,
It is characterized by further comprising means for changing the determination condition of the non-ejection determination.

According to a sixth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to fourth aspects, based on the detected or estimated heat flow rate information,
It is characterized in that it further comprises means for changing a condition of blank ejection for detecting non-ejection.

According to a seventh aspect of the present invention, in the ink jet recording apparatus according to any one of the first to sixth aspects, the ejection drive is performed for the ejection failure detection according to at least the head rank of the recording head. It is characterized in that it further comprises means for changing the condition.

An ink jet recording apparatus according to an eighth aspect of the present invention is the ink jet recording apparatus according to the seventh aspect, further comprising means for changing the non-ejection determination condition in the non-ejection detection according to at least the thermal characteristics of the recording head. Is characterized by.

Further, in the non-ejection detecting method of the ink jet recording apparatus according to the ninth aspect of the present invention, heat is generated from the vicinity of the heating element or the member in which the heating element is formed at the time of detecting the non-ejection or prior to the detection of the non-ejection. It is characterized by detecting or estimating the heat flow velocity to other members or the air that is transmitted, and changing the condition of non-ejection detection according to the information.

In the non-ejection detecting method according to the tenth aspect of the present invention, the heat flow velocity is detected based on at least the temperature change of the print head temperature immediately before the non-ejection detection.

In the non-ejection detection method according to claim 11 of the present invention, the heat flow velocity is estimated by at least the difference between the temperature of the print head at the time of non-ejection detection or immediately before non-ejection detection and the temperature of the environment in which the printing apparatus is placed. It is characterized by performing based on.

In the non-ejection detecting method according to the twelfth aspect of the present invention, the temperature of the heat flow is detected at least at the time of the non-ejection detection or immediately before the non-ejection detection, the temperature of the member in which the heating element is incorporated, and other heat transfer from the temperature. The feature is that it is performed based on the difference from the temperature of the member.

In the non-ejection detecting method according to claim 13 of the present invention, in the configuration according to any one of claims 9 to 12, based on the detected or estimated heat flow rate information,
The feature is that the determination condition for the non-ejection determination is changed.

In the non-ejection detecting method according to claim 14 of the present invention, in the configuration according to any one of claims 9 to 12, based on the detected or estimated heat flow rate information,
The feature is that the condition of blank discharge for detecting non-discharge is changed.

In the non-ejection detecting method according to a fifteenth aspect of the present invention, in the configuration according to any one of the ninth to fourteenth aspects, the ejection performed for the non-ejection detection is performed in accordance with at least the head rank of the recording head. The feature is that the driving condition is changed.

According to a sixteenth aspect of the present invention, in the non-ejection detecting method according to the fifteenth aspect, the non-ejection determining condition for the non-ejection detection is changed in accordance with at least the thermal characteristics of the recording head. There is.

[0040]

Embodiments of the present invention will now be described with reference to the drawings.

(First Embodiment) (1) First, a structural example of an ink jet recording apparatus used in this embodiment will be described.

FIG. 1 shows a serial type ink jet color printer of this embodiment. The recording head 1 is a device that has a plurality of nozzle rows and that ejects ink droplets to perform image recording for dot formation on the recording medium 12 (in this figure, covered by the recording head fixing lever 4). Not directly shown in the figure). Also, as described below,
In this embodiment, in order to eject ink droplets of a plurality of colors,
A plurality of print heads are integrated to form the recording head 1. Ink of different colors is ejected from different print heads, and a color image is formed on the recording medium 12 by mixing these ink droplets.

The print data is the flexible cable 10.
Is transmitted from the electric circuit of the printer body to the print head via the. The print head arrays 1BK (black), 1C (cyan), 1M (magenta), and 1Y (yellow) are integrally configured as recording heads for four colors in this embodiment. The recording head 1 is detachably attached to the carriage 3. In the forward scan of the recording head, ink is ejected in the order of the print head. For example, when making red (hereinafter referred to as R), magenta (hereinafter referred to as M) is first landed on the recording medium 12, and then yellow (hereinafter referred to as Y) is landed on the M dot. Will appear as red dots. Similarly, in the case of green (hereinafter referred to as G), C and Y are landed in order to form a color, and in the case of blue (hereinafter referred to as B), C and
The colors are formed by landing in the order of M. The print heads are arranged with a constant space (P1). Therefore, for example, G solid printing is performed by printing Y solid on C solid. In this G solid printing,
After C is printed, Y is printed with a delay of the movement time of the interval (2 × P1).

The carriage 3 controls the movement in the main scanning direction by detecting the scanning speed and the printing position of the carriage by a position detecting means (not shown). The power source of the carriage 3 is a carriage driving motor, which is transmitted by the timing belt 8 and moves on the guide shafts 6 and 7 in the directions of arrows a and b. Printing is performed during this main scanning operation. The printing operation in the digit direction includes unidirectional printing and bidirectional printing. Normally, in unidirectional printing, printing is performed only when the carriage 3 moves in the opposite direction from the home position (forward direction), and printing operation is not performed in the direction returning to the home position (return direction).
On the other hand, in the bidirectional printing, the printing operation is performed in both the forward and backward directions. Therefore, high speed printing becomes possible.

A preliminary discharge receiver (not shown) is provided near the home position. In order to refresh the ink in the nozzles of the recording head or to detect non-ejection, ejection that is not related to printing may be performed.This preliminary ejection receiver is for receiving ink droplets in that case. Is.

The feeding in the sub-scanning direction is realized by feeding the recording medium 12 by the platen roller 11 driven by a paper feeding motor (not shown). When the recording medium 12 is supplied in the direction of arrow c in the figure and reaches the print position, the print operation is performed by the print head array.

Next, the recording head 1 on the carriage 3 will be described. As shown in FIGS. 4 and 5, the inks BK, C, M, and Y are ejected into the carriage 3 4 respectively.
Two print heads (FIG. 2) and ink tanks 2bk, 2c, 2m, 2y for storing and supplying ink are mounted. Each of these four ink tanks is configured to be attachable to and detachable from the carriage 3, so that a new ink tank can be replaced for each color when ink runs out.

The fixing lever 4 of the recording head is for positioning and fixing the recording head 1 on the carriage 3, and the boss 3b of the carriage 3 and the hole 4a of the recording head fixing lever 4 are rotatably fitted. The recording head 1 can be replaced by opening and closing the lever 4. The recording head fixing lever 4 and the carriage 3 stopper 3d
The recording head 1 is accurately fixed on the carriage 3 by meshing with each other. Further, by joining the contact groups on the recording head 1, the drive signals for driving the discharge heaters of the print heads for four colors, the above-mentioned head characteristics, the diode sensor, etc. can be transmitted or detected from the recording apparatus main body. Become.

Next, details of the recording head 1 will be described. As shown in FIGS. 2 and 3, in the print head 1A that constitutes the recording head 1, in order to eject ink droplets from a plurality of ejection openings A arranged in a row, an applied voltage is supplied and thermal energy is supplied. An electrothermal converter to be generated (hereinafter, discharge heater B) is arranged on the heater board 20G for each discharge port. Then, by applying the drive signal,
The full discharge heater B is heated to discharge ink droplets. The heater board 20G is provided with a discharge heater array 20D in which a plurality of discharge heaters B are arranged side by side, and a dummy resistor 20E that does not discharge a tank droplet is provided in the vicinity thereof. Since the dummy resistor 20E is created under the same conditions as the discharge heater B, the resistance value is measured to detect the generated energy (Watt / hour) of the discharge heater when a constant voltage is applied. it can. The energy generated by the discharge heater is the applied voltage V (V
olt) and discharge heater resistance value R (Ω), V /
Since it can be calculated by R, due to the variation of the resistor,
The characteristics of the discharge heater will change. These resistors may have a variation of ± 15%, for example, when they are created. By detecting the variation in the characteristics of the discharge heater and setting the optimum driving condition for each print head, the life of the print head and the image quality can be improved.

The heater board is adhered to the aluminum board by an adhesive layer. Most of the thermal energy generated by the discharge heater B other than that transferred to the ink is transferred to the aluminum board through the adhesive layer,
Furthermore, it is transmitted to the air around the aluminum board.

Further, in the ink jet printer of this system, thermal energy is applied to the ink to eject the ink, so that the temperature control of the recording head is required. Therefore, a diode sensor 20C is provided on the heater board 20G to measure the temperature in the vicinity of the discharge heater and control the input energy for ink discharge or temperature adjustment.

(2) Measurement of Ejection Heater Characteristic In this embodiment, the recording head 1 has a replaceable structure, and when the head is replaced, the ejection heater characteristic and the ejection heater thermal characteristic are measured (the thermal characteristic of the ejection heater). Will be described later).

The characteristics of the discharge heater are the dummy resistance 20E.
The resistance value of (FIG. 3) is measured. When the constant voltage drive is used for driving the print head, it is possible to know how much energy should be input if the resistance value of the discharge heater is known.

In this embodiment, the case where the variation of the dummy resistor 20E is 272.1Ω ± about 15% will be described. As shown in FIG. 6, the variation in resistance value is divided into 13 ranks. The central value is rank 7, and the width of the resistance value in one rank is about 8Ω, which is about 2.3% of the total variation. If you divide this number of ranks finely, you can set the head rank with higher accuracy.
It is necessary to improve the accuracy of the rank reading circuit on the recording apparatus main body side by the amount of fine division. After the recording device reads the head rank, the memory member (EEP
When writing to ROM, NVRAM, etc.), 1 to 1 above
The number 3 will be stored for each of the 4 heads.

(3) Basic Waveform of Driving Pulse The basic waveform of the driving pulse corresponding to the head rank will be described. Hereinafter, the basic waveform of the drive pulse corresponding to the head rank in this embodiment will be simply referred to as "basic waveform". The basic waveform of this drive pulse is important, and various recording heads are driven based on this.

First of all, the driving at the time of printing is performed on the basis of the above basic waveform. The drive waveform is set according to the head rank so that the ejection state of the recording head is stable and the life of the ejection heater is extended. Therefore, in a normal environment, printing may be performed with the basic waveform as it is, unless the recording head has its own temperature rise due to printing with a particularly high duty. In this embodiment, a double pulse waveform is used as the basic waveform. When the recording head temperature is lower than the predetermined temperature, the temperature is adjusted by the sub heater to compensate the ejection amount. On the contrary, when the temperature of the recording head is equal to or higher than the predetermined temperature, the ejection amount is adjusted by modulating the pulse width of the preceding pulse (preheat pulse) in the shorter direction (PWM control).

Secondly, the preliminary ejection drive is performed based on the basic waveform. Preliminary ejection is performed for the purpose of refreshing the ejection nozzles of the recording head, and it is not necessary to adjust the ejection amount even if the recording head becomes hot and the ejection amount increases. The maximum pulse width of the preheat pulse (that is, the basic pulse waveform itself) is used to improve the recoverability.

When the above-mentioned PWM control is performed, it is required that the pulse width of the preheat pulse of the basic waveform be sufficiently long. That is, in the PWM control, the preheat pulse is shortened as the temperature of the recording head becomes higher,
If the width of the preheat pulse in the basic waveform is short, P
The controllable temperature range in WM control becomes narrow. Therefore, it is not preferable to set the width of the preheat pulse of the basic waveform too small.

However, when the resistance value of the discharge heater (that is, head rank) becomes smaller, the pulse width of the preheat pulse must be shortened accordingly, so that ink bubbling due to the preheat pulse (hereinafter referred to as prefoaming) occurs. Stable discharge cannot be performed.

Therefore, it is necessary to set the preheat pulse of the basic waveform within the range where the above-mentioned harmful effects do not occur,
The pre-pulse width is not set in proportion to the resistance value of the discharge heater.

On the other hand, a pulse relatively after the basic waveform (hereinafter referred to as a main heat pulse) must be changed in accordance with the head rank to obtain a stable ejection state. Therefore, as shown in FIG. The pulse width is set to increase as the head rank increases.

For the above reasons, the basic waveform is constructed as shown in FIG.

(4) Measurement of Thermal Characteristics of Ejection Heater The temperature change between the temperature increase of the recording head due to the idle ejection used for detecting the non-ejection of the recording head and the temperature decrease after the end of the idle ejection is due to the heat generation characteristic of the recording head and the accumulated heat. It is greatly affected by the characteristics. In this embodiment, the ejection heater is driven by the pre-pulse of the basic waveform corresponding to the head rank, and the temperature difference of the temperature rise of the recording head due to it and the temperature difference of the temperature drop from the end of pulse application to a predetermined time later. From, measure the thermal characteristics of the discharge heater.

The heat storage characteristics of the print heads differ from print head to print head due to the degree of joining between members and variations in the discharge amount. Even if the same energy is applied to the discharge heater, a recording head that easily accumulates heat rises to a high temperature, but a recording head that does not easily accumulate heat radiates heat as soon as thermal energy is generated, and does not rise much. Further, the heat generation characteristics differ from print head to print head due to variations in sheet resistance of the discharge heater. In addition, the heat generation characteristics of each main body also differ due to variations in the drive voltage of the heater drive main body power supply of the recording apparatus main body.

In the present embodiment, a pulse having a pre-pulse width of the basic waveform corresponding to the head rank is applied to the discharge heater at 15 kHz for 1 second, and the thermal characteristics of the recording head are measured from the temperature change before and after that.

A method of measuring the thermal characteristics will be specifically described with reference to FIG. First, the temperature (T _{1 in the} figure) of the recording head before pulse application is measured. As described above, a pulse having a preheat pulse width of the basic waveform is applied for 1 second at 15 kHz, and the temperature (T _{2 in the} figure) of the recording head immediately before the end of application is measured. The head temperature is constantly acquired every 20 msec, and a moving average is taken four times in order to suppress noise.

From the measurement results obtained as described above,
The value ΔT _S indicating the thermal characteristics of the recording head is calculated as follows.

[0068]

## EQU1 ## ΔT _S = (T ₁ −T ₂ ) + (T ₂ −T ₃ ) The temperature difference between the temperature rise and the temperature drop is added to the temperature of the recording head, for example, after high-duty printing. This is to avoid the effects of changes in

The pre-pulse width of the basic waveform is sufficiently short, and ink is not foamed by applying a pulse for measuring thermal characteristics. Further, by using the table of the basic waveform for measuring the thermal characteristics of the recording head, there is an advantage that the number of prepared tables can be reduced.

(5) Detection of Heat Velocity from Heater Board After the printing is completed, some time elapses while the carriage moves to the position of the preliminary discharge receiver for the idle discharge of the non-discharge detection. In the present embodiment, between the end of printing before detection of non-ejection and the start of ejection for non-ejection detection (when non-ejection detection is performed from a state in which no ejection is performed, The temperature change of the recording head during the period from the time when the recording head is maintained at the position where the recording head is discharged to the time when the discharge for detecting the non-discharge is started). To detect heat flow to the.

For example, immediately after high-duty printing, when the heat flow rate is high, a large temperature drop of the recording head temperature is measured. Further, when the non-ejection detection is performed from the state where the recording device is not printing, the recording head is not heated, so a large temperature drop is not measured (or rather,
Rather, the temperature has not dropped. ). That is, the heat flow rate is detected based on the degree of temperature decrease of the measured temperature change.

A specific method for measuring the heat flow velocity will be described with reference to FIG. The heat flow velocity is detected from the difference between the head temperature T ₀ when a fixed time has elapsed after the end of printing and the head temperature T ₄ immediately before the idle discharge for non-discharge detection is started after the fixed time has elapsed. To do. The reason why the temperature difference of the temperature decrease from immediately before the end of printing to the start of discharge is not used is that the heat flow rate from the T ₀ position to immediately before the start of discharge is more than the heat flow rate in this case because the non-discharge is detected. This is because it is considered to be close to the heat flow rate during the idle ejection of the recording head and the subsequent recording head leaving. However, if there is sufficient accuracy, the heat flow rate may be detected using the head temperature immediately after the printing is completed.

The influence of the heat flow rate on the non-ejection detection will be described later.

(6) Non-ejection detection In this embodiment, a drive pulse having a basic waveform corresponding to the head rank is applied to the ejection heater, and the temperature difference between the temperature rise of the recording head and the subsequent temperature drop is measured. , A value ΔTi indicating the magnitude of temperature change is calculated. Then, the thermal characteristic ΔT _{S of the} discharge heater is compared with the threshold value ΔT _th for determination determined by the value (T ₀ −T ₄ ) indicating the heat flow rate, and the non-ejection of the recording head is determined.

A method of measuring the value ΔT _i indicating the magnitude of temperature change due to idle discharge for detecting non-discharge will be specifically described with reference to FIG. First, the temperature of the recording head (T _{4 in the} figure) immediately before the start of the idle discharge is measured. Then, the drive pulse of the above-mentioned basic waveform corresponding to the head rank is set to 6.125k.
While applying 5000 shots (about 0.8 seconds) at Hz, the temperature (T _{5 in the} figure) of the recording head immediately before the end of the idle discharge is measured. After that, the temperature of the recording head (T _{6 in the} figure) is measured 0.8 seconds after the end of the idle discharge. The recording head temperature is 20 msec. It is always acquired every time, and a moving average is taken four times to suppress noise.

From the measurement results obtained as described above,
A value ΔT indicating the amount of temperature increase / decrease of the recording head due to idle discharge
_i is calculated as follows.

[0077]

## EQU2 ## ΔT _i = (T ₅ −T ₄ ) + (T ₅ −T ₆ ) Next, the influence of the thermal characteristics of the recording head on the temperature increase / decrease of the recording head will be described. FIG. 10 is a schematic diagram for explaining the influence of the thermal characteristics of the recording head on ΔT _i . More specifically, FIG. 10 shows that the plurality of recording heads in which the heat flow rate is sufficiently small have Δ in the non-ejection state and the normal ejection state.
It shows the characteristic of ΔT _i with respect to T _s . When the recording head is in the non-ejection state, ΔT _i is almost proportional to ΔT _s . When the recording head is in a normal ejection state, the rate of change of ΔT _i with respect to ΔT _s is small,
The relationship is not strictly proportional. The reason for this is that the ejection amount is different due to the difference in the thermal characteristics of the recording heads.
Conceivable. That is, when ΔT _s is large, the temperature rise due to the blank ejection of non-ejection detection is large, the ink temperature in the vicinity of the heater rises, and the ejection amount increases, so that the thermal energy carried out of the recording head by the ejected ink droplets. And ΔT _i becomes slightly smaller than when ΔT _i is proportional to ΔT _s .

Next, the influence of the heat flow velocity of the heat energy flowing out from the heater board on the temperature rise and fall of the recording head due to idle ejection will be described. 11 is one
FIG. 9 is a schematic diagram showing the characteristics of ΔT _i with respect to the above (T ₀ −T ₄ ) measured with respect to two recording heads and in the case where the recording heads are in a non-ejection state and a normal ejection state. Until said (T ₀ -T ₄₎ reaches a t _a is
ΔT _i is almost constant. When the (T ₀ -T ₄₎ is larger than t _a, ΔT _i with increasing (T ₀ -T ₄₎
Is getting smaller. It is considered that this is because, as described above, when the heat flow rate of the heat flowing out from the heater board 20G is large, the heat generated by driving the heating element immediately flows out from the heater board. In addition, (T ₀ −
T ₄₎ <in the region of t _a, the [Delta] T _i is approximately constant, originally heater board 20G and whether it the temperature gradient between the heat outflow destination from is not too large, to start discharging from the end of the previous operation Heater board 20G
It is considered that the temperature gradient at the heat outflow destination is sufficiently small, and the heat flow velocity is small and almost constant.

In consideration of the above phenomenon and variations in ΔT _{s and the} like of the print head, the non-ejection determination threshold ΔT _th is calculated as follows (in FIG. 10, a broken line, in FIG. 11, a dashed line). Shown with.).

[0080]

## EQU3 ## ΔT _th = aΔT _s + b-c (T ₀ -T ₄ ) a and b are constants c is (T ₀ -T ₄ ) ≤t _a , and c = 0 (T ₀ -T ₄ ). > t _a in c> 0 constant ΔTi ≧ ΔT _th ......> misfiring ΔTi <ΔT _th ......> normal discharge (T ₀ -T ₄₎ state of ≦ t _a of (c = 0), the non-ejection determination The situation is shown by a broken line in FIG. Also, (T ₀ −T ₄ )
FIG. 11 shows a state of the non-ejection determination with respect to the change of No. In addition, the flow chart of the control of the non-ejection detection,
It shows in FIG.

As described above, in the present embodiment, prior to the non-ejection detection, the heat flow rate from the heater board incorporating the heating element and the temperature sensor to other members is detected from the temperature change of the recording head, By changing the non-ejection determination threshold value based on the information, even when the temperature change of the temperature rise and fall due to the idle ejection is affected by the heat flow rate,
This makes it possible to detect non-ejection of the recording head. In addition, this method has an advantage that it is not necessary to provide a long waiting time before detection of non-ejection, and therefore the throughput of the recording apparatus is not reduced.

In the present embodiment, the heat flow rate was detected from the two temperature data of T ₀ and T ₄ , but if the measurement data is increased, such as by measuring the head temperature during the time, the detected heat flow is detected. The reliability of the flow velocity data can be further improved.

Further, if the time required for non-ejection detection may be long, the time from the end of printing to the start of idle ejection for non-ejection detection may be extended to increase the number of temperature data measurement points. It is effective to improve the reliability of the data of the heat flow rate.

In this embodiment, although the threshold value for driving the blank ejection or the non-ejection determination is corrected according to the head rank and the thermal characteristics of the recording head, the recording head having a small variation in the thermal characteristics of the head rank is used. If used, of course, no such correction is necessary. However, even in such a case, similarly to the present embodiment, it is necessary to detect the heat flow rate and correct the determination method of the non-ejection determination in order to detect the non-ejection of the print head after high duty driving. Is valid.

(Second Embodiment) (1) Structure of Inkjet Recording Device Used in Second Embodiment In this embodiment, an inkjet recording device having the same structure as in the first embodiment is used. However, it is different in that the temperature sensor is provided in a place that is not easily affected by the temperature rise of the recording head of the recording apparatus main body, and the environmental temperature can be monitored. Further, in the present embodiment, it is assumed that the variation in the sheet resistance of the recording head and the variation in the recording characteristics are small, and the correction by them is not performed.

(2) Estimation of Heat Velocity from Heater Board In this embodiment, the head temperature (T _{4 in} FIG. 13) immediately before the idle discharge for detecting the non-discharge of the recording head and the recording apparatus main body are attached. environmental temperature (hereinafter, referred to as T _e) which is detected by the temperature sensor was used the difference between, that (T ₄ -T _e), to estimate the heat flux from the heater board 20G to another member.

(3) Non-ejection detection In this embodiment, as shown in FIG. 13, a constant number of blank ejections are performed as in the first embodiment, and the temperature rise of the recording head and the subsequent temperature drop occur. The temperature difference is measured, and the value ΔT _i indicating the magnitude of the temperature change is measured.

The correlation between ΔT _i and the difference (T ₄ −T _e ) between the temperature of the print head and the ambient temperature immediately before the idle discharge described above will be described below with reference to FIG. FIG. 14 shows the characteristics of ΔT _i when a print head is in a non-ejection state and when the print head is in a normal ejection state, corresponding to (T ₄ −T _e ). Is. (T ₄
ΔT _i is (T ₄ −T) until −T _e ) reaches t _b.
It is almost constant regardless of the value of _e ), but (T ₄ −T
_{When e} ) exceeds tb, it becomes smaller as (T ₄ −T _e ) increases. This is the same phenomenon as that described in the first embodiment.

In the present embodiment, the correction based on the heat flow rate and the determination of non-ejection are performed as follows.

When (T ₄ −T _e ) ≦ t ΔT _i ≧ ΔT _th ……> Non-ejection ΔT _i <ΔT _th ……> Normal ejection (T ₄ −T _e )> t ΔT _i −a · (T ₄ −T _e ) ≧ ΔT _th ……> Non-ejection ΔT _i −a · (T ₄ −T _e ) <ΔT _th ……> Normal ejection ΔT _th is a threshold value for non-ejection determination and is a constant. Is.

In this way, ejection failure can be detected regardless of the heat flow rate. FIG. 15 shows a flowchart of the non-ejection detection of this embodiment.

The recording heads used in the first and second embodiments have a structure in which a heater board is adhered to an aluminum board with an adhesive layer as shown in FIG. The configuration is not limited to this. For example,
Even in the case where the recording head used in this example does not have an aluminum board, or in the case where a heat-generating element for ejecting ink droplets directly on the heat sink is formed, after performing high-duty printing, the vicinity of the ejection element Since the heat flow rate from the ink is increased, the temperature rise due to the idle ejection may decrease, and even in such a case, in order to detect the ejection failure without decreasing the throughput of the recording apparatus,
The present invention is effective.

A heating element is directly formed on the heat sink,
If the heat sink is sufficiently large and has a large cooling effect, the heat flow velocity of heat propagation from the vicinity of the heater due to the thermal gradient in the heat sink may have a great influence on the temperature rise due to idle discharge. In this case, the present invention is similarly effective.

(Third Embodiment) (1) Configuration of Inkjet Recording Device Used in Third Embodiment This embodiment has substantially the same configuration as that of the first embodiment. In the ink jet recording apparatus used in this embodiment, a temperature sensor is provided on the aluminum board shown in FIG.
It is possible to monitor the temperature of the aluminum board. In this recording head, the aluminum board functions as a heat dissipation plate, and the aluminum board is sufficiently large, and the temperature difference between the heater board 20G and the aluminum board mainly contributes to the speed of heat dissipation from the heater board 20G. It is assumed that

(2) Estimation of Heat Flow Velocity from Heater Board In this embodiment, a temperature difference (temperature gradient) between the temperature sensor provided on the heater board and the temperature sensor provided on the aluminum board is detected. Then, the heat flow rate from the heater board is estimated. The difference between the value T _{4 of the} temperature sensor provided on the heater board immediately before the start of the blank discharge for detecting the non-discharge and the value T _A of the temperature sensor on the aluminum board at that time (T ₄ −T _A ). Is used to estimate the heat flux from the heater board.

(3) Non-ejection detection In the present embodiment, the blank ejection for non-ejection detection is performed, the temperature difference between the temperature rise of the recording head and the subsequent temperature drop is measured, and the magnitude of the temperature change is determined. The indicated value ΔT _{i is} calculated.

The correlation between the difference (T ₄ −T _A ) between the temperature of the print head and the ambient temperature (sensor temperature on the aluminum board) just before the above-described idle discharge and ΔT _i will be described below with reference to FIG. explain. FIG. 16 shows the characteristics of ΔT _i when a print head is in a non-ejection state and when it is in a normal ejection state with respect to one print head, for (T ₄ −T _A ). To (T ₄ -T _A) reaches t _c is, [Delta] T _i is, (T ₄ -T _A) regardless of the value of is substantially constant, exceeds (T ₄ -T _A) is t _c And (T ₄
-It becomes smaller as T _A increases. This is the same phenomenon as that described in the first embodiment.

In this embodiment, the number of blank discharges is changed by (T ₄ −T _A ) obtained as described above, and thereby the heat flow rate from the heater board is corrected. is there. The number of blank discharges is determined as follows.

[0099] (T ₄ -T _A) ≦ t the case of _{c 6.125kHz} 5000 shots (T ₄ -T _A)> In the case of _{t c 6.125kHz 5000 + a · (} T 4 -T A) onset a is a constant (T _4- T _A )> t _c , and as the number of blank discharges increases, the time required for blank discharge also increases. Along with that, the temperature of the recording head after cooling from the end of the idle discharge (in FIG. 13,
Also increase the time allowed to stand until the measurement of T ₆ ).

Using ΔT _i measured as described above, the ejection failure is determined as follows.

ΔT _i ≧ ΔT _th ......> Non-ejection ΔT _i <ΔT _th ......> Normal ejection ΔT _th is a threshold value for non-ejection determination and is a constant.

As described above, it is possible to detect the non-ejection regardless of the slow speed of the heat flow. In the configuration of the present embodiment, even when the heat flow rate is high and the temperature rise due to the blank discharge is small, the temperature rise is increased by increasing the number of blank discharges, so that the temperature change of the temperature rising / falling becomes large. , The SN ratio can be maintained in a good state. FIG. 17 is a flowchart showing the control of this embodiment.

In the present embodiment, as described above, the effect of the heat flow rate is corrected by estimating the heat flow rate and correcting the number of idle discharges. However, instead of changing the number of idle discharges, driving is performed. Even if it is corrected by voltage or drive waveform,
The same effect can be obtained.

In the second and third embodiments, the correction of the non-ejection detection determination condition and the non-ejection detection idle ejection drive condition based on the head rank and thermal characteristics of the recording head performed in the first embodiment is performed. Didn't do it. However, when there are large variations in the heat generation characteristics and heat dissipation characteristics of the print head, or when the margin of durability of the print head is small, the judgment conditions for non-ejection detection based on the head rank and thermal characteristics of the print head, and non-ejection Even in such a case, the non-ejection detection with higher accuracy can be performed by correcting the drive condition of the blank ejection for detection, and the recording head can be protected by controlling the input energy. You can

In the first to third embodiments, when the heat flow velocity is larger than a predetermined value, ΔT _{i in} that case is set.
The heat flow velocity was corrected by approximating the characteristics of
The present invention is not limited to such a configuration. If more precise correction is required to obtain sufficient accuracy of non-ejection detection, non-linear expression may be used for correction, or lookup of correction amount for non-ejection detection with respect to the magnitude of heat flow rate. It is also possible to perform more precise correction using the table. Further, the correction amount or the correction method may be selected for each area by dividing the area into more areas.

In the first to third embodiments, there has been described the case where there is a sufficient margin for non-ejection determination even when the heat flow velocity increases, but when the heat flow velocity increases, the margin for non-ejection determination increases. If the accuracy of the non-ejection judgment is significantly reduced due to the decrease, the waiting time is set from the end of printing to the detection of non-ejection based on the information of the heat flow rate, and the non-ejection occurs after the heat flow rate becomes sufficiently small. The method of detection is effective.

(Others) In particular, the present invention is provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink, especially 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,
It can be applied to any of the continuous type, but especially 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. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble 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, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection 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 main body of the apparatus, or the electrical connection to the main body of the apparatus or the ink from the main body of the apparatus by being attached to the main body of the apparatus. 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.

Regarding the type and the number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, and 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 lower 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, besides the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function are provided. It may be a form or the like.

[0115]

According to the present invention, prior to the non-ejection detection or the non-ejection detection, the heat flow velocity to the other member or the air to which the heat is transmitted from the vicinity of the heating element or the member having the heating element is detected or estimated. However, by changing the non-ejection detection condition based on the information, the throughput is lowered even immediately after high-duty printing, even when the heat flow velocity is high in the vicinity of the heating element or from the member in which the heating element is built. It has become possible to detect non-ejection.

[Brief description of drawings]

FIG. 1 is a perspective view showing an entire conventional recording apparatus.

FIG. 2 is a perspective view showing the structure of a recording head to which the present invention is applied.

FIG. 3 is a configuration diagram on a heater board of a print head that constitutes the recording head.

FIG. 4 is a perspective view showing a carriage on which the recording head is mounted.

FIG. 5 is a perspective view showing a mounted state of a recording head of the carriage.

FIG. 6 is a table showing the correspondence between head ranks and resistance values of dummy resistors in the first embodiment of the present invention.

FIG. 7 is a diagram showing a table of basic waveforms corresponding to head ranks in the first embodiment of the present invention.

FIG. 8 is a graph illustrating the measurement of the thermal characteristic ΔT _s of the recording head according to the first embodiment of the invention.

FIG. 9 is a graph illustrating the measurement of the heat flow rate and the measurement of the temperature rise / decrease ΔT _i due to the non-discharge detection idle discharge in the first embodiment of the present invention.

FIG. 10 is a graph showing a correlation between thermal characteristics ΔT _s of the recording head and ΔT _i in the first embodiment of the present invention.

FIG. 11 is a graph showing a correlation between ΔT _i and a value (T ₀ −T ₄ ) indicating a heat flow rate from a member having a heating element built therein to another member in the first embodiment of the present invention.

FIG. 12 is a flowchart showing measurement of heat flow velocity and detection of non-ejection in the first embodiment of the present invention.

FIG. 13 is a graph illustrating the measurement of the temperature increase / decrease ΔT _i by idle discharge for non-discharge detection in the second example of the present invention.

FIG. 14 shows the ΔT _i in the second embodiment of the present invention.
And the difference between the temperature of the recording head and the ambient temperature (T ₄ −T _e ).
It is a graph which shows correlation with.

FIG. 15 is a flowchart showing measurement of heat flow velocity and detection of non-ejection in the second embodiment of the present invention.

FIG. 16 shows the ΔT _i in the third embodiment of the present invention.
When is a graph showing the correlation between a difference between the temperature of the temperature and the aluminum board heater board (T ₄ -T _A).

FIG. 17 is a flowchart showing measurement of heat flow rate and non-ejection detection in the third embodiment of the present invention.

FIG. 18 is a graph showing a difference in temperature rise / decrease of the recording head when the recording head in the room temperature environment and the recording head after the driving temperature rise are driven by a constant number of times in the conventional recording apparatus.

FIG. 19 is a graph showing the relationship between the heat capacity and the temperature of the recording head and peripheral members when the recording head in the room temperature environment and the recording head after the driving temperature is raised are driven a fixed number of times in the conventional recording apparatus. 1A is a graph for a recording head in a room temperature environment, and FIG. 1B is a graph for a recording head after driving and heating.

[Explanation of symbols]

 1 Recording Head 1A Printing Head 2 Ink Tank 3 Carriage 4 Recording Head Fixing Lever 6 Guide Axis 7 Guide Axis 8 Timing Belt 9 Pulley 10 Flexible Cable 11 Platen Roller 12 Recording Medium 13 Ink A Discharge Port B Discharge Heater 20C Diode Sensor 20D Discharge Heater Row 20E Dummy resistor 20F Sub heater 20G Heater board 21 Aluminum board 22 Adhesive layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B41J 3/04 104 K

Claims (16)

[Claims] 1. A non-ejection determination for determining a non-ejection of a print head based on any one of a mutual relationship between a temperature change due to a temperature rise caused by idle ejection of a print head, a temperature change due to a temperature decrease after ejection, or both temperature changes. In an ink jet recording apparatus having means, prior to detection of non-ejection or prior to detection of non-ejection, heat flow velocity to other members or air to which heat is transmitted from the vicinity of the heating element or the member with the heating element is detected or estimated. An inkjet recording apparatus is provided with a correction unit that changes the condition of non-ejection detection according to the information. 2. The correction means detects the heat flow rate,
The inkjet recording apparatus according to claim 1, wherein the recording is performed based on at least a temperature change of the recording head temperature immediately before detection of non-ejection. 3. The correction means estimates the heat flow rate,
The inkjet recording apparatus according to claim 1, wherein the recording is performed based on at least a difference between a temperature of the recording head at the time of detecting non-ejection or immediately before detection of non-ejection and a temperature of an environment in which the recording apparatus is placed. 4. The correction means detects the heat flow rate,
2. The ink jet recording according to claim 1, wherein the recording is performed based on at least a difference between a temperature of a member in which a heating element is formed at the time of non-ejection detection or immediately before non-ejection detection and a temperature of another member to which heat is transmitted from the member. apparatus. 5. The ink jet recording according to claim 1, further comprising means for changing the determination condition for the non-ejection determination based on the detected or estimated heat flow rate information. apparatus. 6. The method according to claim 1, further comprising means for changing a condition of idle discharge for detecting non-discharge based on the detected or estimated heat flow rate information.
The inkjet recording device according to any one of 1. 7. The apparatus according to claim 1, further comprising means for changing a driving condition of ejection performed for detecting the non-ejection in accordance with at least a head rank of a recording head. Inkjet recording device. 8. The ink jet recording apparatus according to claim 7, further comprising means for changing a non-ejection determination condition in the non-ejection detection according to at least a thermal characteristic of a print head. 9. Ink jet recording for determining non-ejection of a print head based on any one of a temperature change due to a temperature rise due to a blank discharge of the print head, a temperature change due to a temperature drop after the discharge, or a mutual relation between both temperature changes. In the non-ejection detection method of the device, when the non-ejection is detected or prior to the non-ejection detection, the heat flow velocity to the other member or the air where the heat is transmitted from the vicinity of the heating element or the member with the heating element is detected or estimated. Then, the non-ejection detection method of the ink jet recording apparatus is characterized by changing the non-ejection detection condition according to the information. 10. The non-ejection detection method for an ink jet recording apparatus according to claim 9, wherein the detection of the heat flow velocity is performed based on at least a temperature change of the print head temperature immediately before the non-ejection detection. 11. The heat flow velocity is estimated based on at least the difference between the temperature of the print head at the time of detection of non-ejection and immediately before the detection of non-ejection and the temperature of the environment in which the printing apparatus is placed. 9. The method for detecting non-ejection of an inkjet recording apparatus according to item 9. 12. The heat flow velocity is detected based on at least a difference between a temperature of a member in which a heating element is formed at the time of detection of ejection failure or immediately before detection of ejection failure and a temperature of another member to which heat is transferred. The non-ejection detection method for an inkjet recording apparatus according to claim 9. 13. The non-ejection detection of the ink jet recording apparatus according to claim 9, wherein the non-ejection determination condition is changed based on the detected or estimated heat flow rate information. Method. 14. The ink jet recording apparatus according to claim 9, wherein a condition of idle ejection for detecting non-ejection is changed based on the detected or estimated heat flow rate information. Non-ejection detection method. 15. The ink jet recording apparatus according to claim 9, wherein a driving condition of the ejection performed for detecting the non-ejection is changed according to at least a head rank of the recording head. Non-ejection detection method. 16. The non-ejection detection method for an ink jet recording apparatus according to claim 15, wherein the non-ejection determination condition in the non-ejection detection is changed in accordance with at least the thermal characteristics of the print head.