JP2002178492A - Ink jet recording apparatus, method for detecting temperature characteristics of ink jet recording head, and method for judging discharge state of ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the temperature characteristics of a recording head caused by the heat value or heat outflow quantity of the recording head adaptable to various uses among individual differences of the recording head. SOLUTION: The temperature characteristics of the recording head are known on the basis of the temperature change of the recording head at the time of application of predetermined energy to the heater of the recording head. The threshold value at the time of detection of the non-discharge state of the recording head is determined by utilizing the temperature characteristics to accurately judge whether or not the ink discharge state of the recording head is good.

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 which can be used as a recording apparatus such as a printer, a facsimile apparatus, a word processor, a copying machine and the like generally used for office equipment. Further, the present invention relates to a method for detecting a temperature characteristic of an ink jet recording head and a method for judging a discharge state of the ink jet recording head.

[0002]

2. Description of the Related Art Conventionally, recording apparatuses for recording on recording media such as paper and OHP sheets have been put to practical use in the form of mounting recording heads of various recording systems. This recording head includes a wire dot type, a thermal type, a thermal transfer type, an ink jet type, and the like. In particular, the ink jet method has attracted attention as a quiet recording method with a low running cost because ink is directly discharged onto a recording medium.

In such an ink jet recording apparatus, an ink tank storing ink and a recording head are connected by an ink supply pipe or the like, and ink is supplied from the ink tank. The ink tank is divided into a recording head, and is an ink cartridge type that is exchangeably mounted in the recording apparatus separately from the ink tank, or a recording head that is integrated with the recording head and is exchangeably mounted in the recording apparatus. An integrated type has been put to practical use.

In the above-described ink jet recording apparatus, if the supply of ink is interrupted due to the consumption of ink, the ink cannot be ejected and recording cannot be performed, so that the purpose of the recording apparatus cannot be achieved. In order to avoid such a trouble, a recording apparatus having a function of detecting a remaining amount of ink for generating a warning signal or requesting replacement of an ink tank according to the amount of consumed ink has been put to practical use.

In the conventional ink remaining amount detection method as described above, a method of counting the pulse signal applied for ink ejection and calculating the amount of ink consumption, the resistance value of the ink itself or the holding member for holding the ink, or the like. A method that monitors changes, a method that detects changes in the weight of ink tanks, and a method that provides a transparent area in the ink path of the ink tank or print head, and detects the presence or absence of ink on the path by a photo sensor or visually by the user Etc. have been devised.

In the above-described method using the count of the ink discharge pulse signal for detecting the remaining amount, the amount of ink used for recording is calculated by the product of the number of applied pulses and the amount of ink discharged per pulse. Then, the remaining amount is detected.

The method of monitoring the resistance value of the ink or the like and detecting the remaining amount is based on the fact that widely used ink has specific resistance including water, a conductive substance and the like. By detecting the resistance value of the ink and the holding member holding the ink, the remaining amount is detected by utilizing the fact that the resistance value between the electrodes changes with a correlation with the ink amount.

In the method utilizing the weight change of the ink tank, a spring member or the like is provided on a mounting member to which the ink tank is mounted, and a change in the force applied to the spring member due to the consumption of ink is used to expand and contract the spring. The remaining amount is detected by, for example, operating an electric contact that comes in contact with or separates from the terminal in accordance with the condition.

[0009]

However, the above-mentioned prior art has the following problems.

[0010] Even if the remaining amount of ink which is considered to be unrecordable by the above-described method is detected, the value is affected by individual differences in the manufacture of the print head, etc., and when a remaining amount warning is issued,
There is a problem that the accuracy of the detection result is low, such as a case where recording is not possible immediately after the warning or a case where recording can be normally performed after a lapse of a predetermined time after the warning. According to the results of experiments conducted by the present inventors, the above problem was remarkable in a recording head in which ink was held in an ink tank using an ink holding member such as a sponge.

In addition, the amount of ink droplets ejected per pulse ejected by the pulse depends on the environmental temperature in addition to the individual differences of the recording head, so that it is difficult to calculate an accurate ink amount. There has been a problem that the accuracy is not sufficient even by visual observation or state detection by a photo sensor.

There are also problems that a detecting member such as a spring member or a photo sensor is required for detecting the remaining amount, and that the configuration becomes complicated by providing a transparent area in the ink path.

Further, in the above-mentioned conventional example, it is possible to detect an unrecordable state due to interruption of ink supply due to ink consumption, but to detect an unrecordable state which may occur before the ink is completely consumed. There is also the problem of difficulty. Before the ink is exhausted, the unrecordable state means that before the ink is exhausted, air enters the ink path such as the ink supply pipe that connects the ink tank and the recording head, and bubbles are generated. In the recording head that causes foaming, residual bubbles are generated and grow,
This is caused when the ink supply is interrupted, or when the recording device or the recording head is vibrated to destroy the meniscus at the ink ejection port and air flows into the nozzle of the recording head from the ink ejection port. is there. As a method of detecting that the ink supply has been interrupted due to such depletion of the ink or other factors, the ink cannot be normally ejected and the ink cannot be ejected, that is, the recording has become impossible. There is a method for detecting the temperature of the head. That is, in a state where ink cannot be normally ejected from the recording head, even if the element for ejecting ink is driven, ink is not ejected, and as a result, the temperature of the recording head rises. , It is possible to detect the ejection state of whether or not the ink can be ejected.

However, the temperature characteristics such as the amount of heat generated and the amount of heat released differ from printhead to printhead.
In the detection of the ejection state, even if the threshold for judging that the recording is not possible is set to a certain temperature, even if the ejection can be performed normally due to the variation in the temperature characteristics of each recording head, the ejection may be erroneously performed. In some cases, the state may be detected as an improper state, or it may be detected that the ejection is not performed and the recording is in an improper state.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a main object of the present invention is to provide a recording head having temperature characteristics that vary from one recording head to another. Another object of the present invention is to provide a method for detecting the temperature characteristics of a recording head so that it is possible to accurately determine whether or not ink can be normally ejected. And

[0016]

According to the present invention, there is provided a recording head having an electrothermal converter for generating thermal energy in response to application of an electric signal and a discharge port for discharging ink. In an ink jet recording apparatus which is mounted so as to be exchangeable and discharges ink onto a recording medium from the mounted recording head to perform recording, a temperature detecting means for detecting a temperature of the recording head, and an individual of the recording head Temperature characteristic detecting means for detecting a temperature characteristic that varies due to a difference in the amount of heat generation or heat outflow for each, the temperature characteristic detecting means, in a step different from the recording on the recording medium, A predetermined electric signal is applied to the electrothermal transducer of the recording head, and the recording head caused by the heat energy generated by the electrothermal transducer by the application of the electric signal. Based temperature change in the result of detection by said temperature detecting means, and detecting the temperature characteristics of the recording head is mounted.

According to the present invention, an ink jet recording head having an electrothermal transducer for generating thermal energy in response to application of an electric signal and a discharge port for discharging ink is exchangeably mounted, and is mounted. A method for detecting a temperature characteristic of the ink jet recording head in an ink jet recording apparatus for performing recording by discharging ink from the formed ink jet recording head to a recording medium, wherein in a process different from a recording process, Applying a predetermined electrical signal to the electrothermal transducer of the inkjet recording head mounted on the inkjet recording head; and applying the predetermined electrical signal to the inkjet recording caused by thermal energy generated by the electrothermal transducer. Detecting a temperature change of the head; and detecting the ink temperature based on the detected temperature change. Varies due to the difference Tsu preparative heating value of each of the recording heads or thermal runoff, the steps of detecting the temperature characteristics of the ink jet recording head, characterized by comprising the.

Further, according to the present invention, a judgment is made as to whether the ink ejection state of the ink jet recording head is good or not based on the temperature characteristics of the ink jet recording head detected by the above method. Is provided.

(Action) Based on the configuration of the present invention, in an ink jet recording apparatus which performs recording by discharging ink from a discharge port to a recording medium and performs recording by using a replaceable recording head, the individual difference of the recording head is determined. Among them, it is possible to detect the temperature characteristics of the recording head, which can be applied to various uses and are caused by the amount of heat generated by the recording head and the amount of heat flowing out.

According to the present invention, it is possible to provide a method of detecting a temperature characteristic of a recording head so that it is possible to accurately determine an ink discharge state as to whether or not ink can be discharged normally. .

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described in detail with reference to the drawings.

Embodiment 1 FIG. 1 is a perspective view of a head cartridge 3 in which a recording head 1 and an ink tank 2 are integrated, and FIG. 2 is an exploded perspective view of the head cartridge 3. Reference numeral 110 denotes a heater board on which a plurality of discharge heaters arranged in a row on a Si substrate and electric wiring for supplying electric power thereto are formed. 140 is
A grooved top plate, in which a plurality of nozzles, an orifice plate 141 having discharge ports corresponding to the nozzles, a common liquid chamber for storing ink to be supplied to the nozzles, and the like are integrally formed. Reference numeral 120 denotes a wiring board. One of the wirings is connected to the heater board 110 by wire bonding or the like, and the other end has a pad 121 for receiving an electric signal from the printing apparatus main body. Reference numeral 130 denotes a metal base plate to which the wiring board 120 and the heater board 110 are attached with an adhesive or the like.

Further, the heater board 110 and the grooved board are formed by engaging the feet of the presser spring with the holes 131 of the base plate 130 with the presser spring 150 sandwiching the heater board 110 and the grooved top plate 140. The top plate 140 is fixed to the base plate 130 by pressure bonding. Reference numeral 160 denotes an ink supply member having an ink supply pipe 161 and an ink conduit 162 connected thereto. Ink supply pipe 161
Is connected to the ink supply hole 101 of the ink tank 100, and the ink conduit 162 is connected to the ink receiving port 142 of the grooved top plate 140. Thereby, the ink tank 10
An ink flow path is formed from 0 to the ejection port of the orifice plate 141.

FIG. 3A shows the structure of the heater board 110.
FIG. 3B is a partially cutaway perspective view of FIG. Reference numeral 111a denotes a discharge heater, and reference numeral 111 denotes a discharge heater array, which is provided corresponding to each of the nozzles following the discharge port of the orifice plate 141.
By applying a voltage to the ejection heater array 111, the ink in the nozzles obtains thermal energy and is ejected as droplets from ejection openings of the orifice plate 141, thereby performing recording. Reference numerals 112a and 112b denote heaters for controlling the temperature of the recording head, which can heat the vicinity of the heater board 110. 113a and 113b are the discharge heater row 111 and the heaters 112a and 112b.
A temperature sensor that can be manufactured at the same time by a semiconductor film formation technique in the same manner as described above, and can detect the temperature near the ejection heater array 111.

The hatched portion indicates the position of the connection with the grooved top plate 140. In addition, the discharge heater row 111
Each is an electrothermal converter having a resistance value of 120Ω, and outputs about 3 W of energy at a drive voltage of 19 V. The heaters 112a and 112b are electrothermal converters having a resistance value of 144Ω, and output 4 W of energy at a driving voltage of 24 V. The temperature sensors 113a and 113b are diode sensors, and the output value changes by about 2.5 mV per degree of temperature.

Next, the principle of ejection of a recording head used as a recording means in the ink jet recording apparatus of this embodiment will be described.

A recording head section applied to an ink jet recording apparatus generally has a fine liquid discharge port (orifice),
The liquid passage and the energy acting portion provided in a part of the liquid passage, and an energy generating means for generating droplet forming energy to act on the liquid in the acting portion are exchangeable. As an energy generating means for generating such energy, one using an electromechanical transducer such as a piezo element, or irradiating an electromagnetic wave from a laser or the like, absorbing the liquid there to generate heat, and Discharges droplets by the action of heat generation,
There is a type in which the liquid is caused to fly, or a type in which the liquid is discharged by heating the liquid with an electrothermal converter.

Among them, a recording head portion used in an ink jet recording method for discharging a liquid by thermal energy has a high liquid discharge port (orifice) for discharging a recording droplet to form a flying droplet. Since it can be arranged at a high density, it is possible to record at a high resolution. In addition, a recording head using an electrothermal transducer as an energy generating means can easily be made compact as a whole as a recording head, and has recently made remarkable progress in technology and reliability in the field of semiconductors. Multi-nozzle, because it can make full use of the advantages of technology and micro-machining technology, and it is easy to make it long and planar (binary).
It is possible to provide an ink jet recording head that can be easily mounted at high density, has high productivity in a large amount, and has a low manufacturing cost.

In general, an ink jet recording head manufactured through a semiconductor manufacturing process using an electrothermal transducer as an energy generating means is provided with a liquid path corresponding to each ink ejection port. An electrothermal converter is provided as a means for applying thermal energy to the liquid filling the liquid path and discharging the liquid from the corresponding ink discharge port to form a flying droplet. Has a structure in which liquid is supplied from a common liquid chamber communicating with each liquid path. Regarding the method of manufacturing the ink discharge section, the present applicant has proposed that a solid layer for forming at least a liquid path on the first substrate and an active energy ray-curable material layer used for forming at least a wall of the liquid path include: , A second substrate is sequentially laminated, a mask is laminated on the second substrate, and an active energy ray is irradiated from above the mask to form at least a liquid path of the active energy ray-curable material layer. Curing the wall as a component,
Further, a method has been filed in which an uncured portion of the solid layer and the active energy ray-curable material layer is removed from between the two substrates to form at least a liquid path (see JP-A-62-253457).

FIG. 3C is a schematic view of the above-described ink jet recording head. The recording head portion 1801 is formed by an electrothermal converter 1803, an electrode 1804, a channel wall 1805, and a top plate 180 formed on a substrate 1802 through semiconductor manufacturing process steps such as etching deposition and sputtering.
6.

However, such a recording head section 1801
In this case, a recording liquid 1812 is supplied from a liquid storage chamber (not shown) into a common liquid chamber 1808 through a liquid supply pipe 1807.

Reference numeral 1809 denotes a liquid supply pipe connector.
The recording liquid 1812 supplied into the common liquid chamber 1808 is supplied into the liquid path 1810 by capillary action, and is stably held by forming a meniscus at the ink discharge port 1811 at the leading end of the liquid path. Then, when electricity is supplied to the electrothermal converter 1803, the liquid on the electrothermal converter surface is heated, a bubbling phenomenon occurs due to film boiling, and droplets are ejected from the ink ejection port 1811 due to the growth of the bubbles. With the above-described configuration, an ink jet recording head unit having a multi-liquid path of 128 liquid paths or 250 liquid paths can be formed with a high-density liquid path arrangement such as a liquid path density of 16 liquid paths / mm.

FIG. 4 shows an example of the configuration of the printer unit of the ink jet recording apparatus according to this embodiment. Here, 201 is a head cartridge having an inkjet recording head,
Reference numeral 202 denotes a carriage on which this is mounted to scan in the S direction in the figure. 203 is the head cartridge 20
Hook for attaching 1 to carriage 202, 20
Reference numeral 4 denotes a lever for operating the hook 203. 20
Reference numeral 5 denotes a support plate for supporting an electrical connection to the head cartridge 201. Reference numeral 206 denotes an FPC (flexible printed circuit) for connecting the electrical connection unit and the main body control unit. 207 is the carriage 202
A guide shaft for guiding the carriage 20
The second bearing 208 is inserted.

At 209, the carriage 202 is mounted.
This is a timing belt for transmitting a power for moving this in the S direction, and is stretched around pulleys 210A and 210B arranged on both sides of the apparatus. A driving force is transmitted to one pulley 210B from a carriage motor 211 via a transmission mechanism such as a gear. A conveyance roller 212 regulates the recording surface of a recording medium such as paper and conveys the recording medium during recording or the like. The conveyance roller 212 is driven by a conveyance motor 213. Reference numeral 214 denotes a paper pan for guiding the recording medium to the recording position, and 215, which is disposed in the middle of the recording medium feeding path and transports the recording medium to the transport roller 2.
12 is a pinch roller for pressing and transporting the same.

A platen 216 faces the discharge port of the head cartridge 201 and regulates the recording surface of the recording medium. A discharge roller 217 is disposed downstream of the recording position in the recording medium transport direction, and discharges the recording medium toward a discharge port (not shown). Reference numeral 218 denotes a spur provided corresponding to the paper discharge roller 217, which presses the paper discharge roller 217 via the recording medium to generate a conveyance force of the recording medium by the paper discharge roller 217. 21
9 is a pinch roller 21 for setting a recording medium or the like.
5, a release lever for releasing the bias of each spur 218;

The both ends of the platen 216
A plurality of portions 212A are rotatably supported by the shaft 17 and are urged toward the front portion 221 of the paper pan 214 from the stop position of the left and right plates 220, and provided at a portion 212A where the transport roller 212 is smaller than the outermost periphery. Is in contact with the inside of the entire surface 221 of the paper pan.

Reference numeral 222 denotes a cap formed of an elastic material such as rubber which faces the ink discharge port forming surface of the recording head at the home position, and is supported so as to be capable of coming into contact with and detaching from the recording head. The cap 222 is used for protection of the recording head at the time of non-recording or the like, and at the time of recovery processing of the recording head.

As a specific example of the ejection recovery process, the cap 222 is opposed to the ejection port forming surface, and an energy generating element provided in the nozzle of the recording head and used for ejecting ink is driven to perform full ejection. A process (preliminary ejection) for ejecting ink from the outlet to remove air bubbles and dust, which are factors causing ejection failure, or ink that has become unsuitable for recording due to thickening, or separately from the ejection port forming surface. There is a process for removing the cause of ejection failure by forcibly sucking and ejecting ink from all ejection ports using a suction pump in a state of being covered with the cap 222.

Reference numeral 223 denotes a suction force for forcibly discharging ink, and a cap 2 for discharging recovery processing by the forced discharge and discharging recovery processing by the preliminary discharge.
This is a pump used for sucking the ink received by 22. Reference numeral 224 denotes a waste ink tank for storing the waste ink sucked by the pump 223.
The waste ink tank 224 is connected to the pump 223 by 228 tubes.

Reference numeral 225 denotes a blade for wiping the ejection port forming surface of the recording head. The blade 225 protrudes toward the recording head and performs wiping during the movement of the carriage. It is movably supported. Reference numeral 226 denotes a motor, and 227 denotes a cam device for receiving power transmitted from the motor 226 to drive the pump 223 and move the cap 222 and the blade 225, respectively.

FIG. 5 is a block diagram showing an example of the configuration of a control system of the printing apparatus having the configuration described above.

The cap position and the movement position of the carriage 202 can be known based on the detection of the recovery system home sensor 235 and the carriage home sensor 236. In the figure, reference numeral 1000 denotes an MPU for executing a control procedure such as a preset program to control each unit, 1001 a ROM storing a program corresponding to the control means, and 1002 a ROM for executing the control procedure. Used as a work area in the RAM.

Hereinafter, a method of measuring the temperature characteristics of the above-described recording head and a method of detecting the ink ejection state using the same will be described in detail.

FIG. 6 is a graph showing a temperature change near the heater board 110 when electric energy is applied to the discharge heater 111.

A curve A represents a case where normal ink ejection is performed, and a curve B represents an ink ejection due to insufficient filling of the ink in the liquid path of the nozzle of the recording head and the common liquid chamber communicating therewith. Is not performed. From the figure, it can be seen that the temperature change is larger when ink is not ejected (curve B) than when ink is ejected (curve A). Generally, the temperature of the heater board 110 is determined by the inflow of heat from the discharge heater 111 as a heat source,
It is determined by the heat flowing out to the base plate 130, the grooved top plate 140, and the like. At this time, when ink ejection is performed,
Since the ink absorbs heat and is released to the outside, the outflow of heat is greater than when ink is not ejected. For this reason, as shown in the figure, there is a difference in the characteristics relating to the temperature rise of the recording head between the case where the ink ejection state is normal and the case where the ink ejection state is defective.

Therefore, it is possible to detect whether or not the ink can be ejected according to the temperature rise near the heater board 110 when predetermined electric energy causing ink ejection is applied to the ejection heater 111.

More specifically, the following may be performed. First, the temperature change dTA in the vicinity of the heater board 110 when applying predetermined electric energy for causing ink discharge to the discharge heater 111 in a state where the ink in the nozzle and the subsequent common liquid chamber are sufficiently filled with ink is measured. Keep it. Similarly, the temperature change dTB after a lapse of a predetermined time in a state where there is no ink in the nozzle and the common liquid chamber subsequent thereto is measured. When these measurements are performed on a large number of head cartridges by statistical processing, a graph as shown in FIG. 7A is obtained. In this way, the maximum value TA of dTA and dT
The minimum value TB of B is obtained in advance.

FIG. 11 is a flowchart showing the sequence of the ink discharge state detection processing executed by the MPU 1000. The program for executing this processing is stored in the ROM 10
01 is stored. In this process, ink can be ejected regardless of variations in temperature characteristics (also referred to as thermal characteristics because of the amount of heat) of each printhead due to the difference in the amount of heat generation and the amount of heat outflow for each printhead. The first method will be described below in accordance with the above flow. First, the predetermined electric energy is applied to the discharge heater 111 (step S1). Next, the temperature change dT near the heater board 110 is measured using the print head temperature sensor 113 (step S2), and this value is compared with TA and TB (steps S3 and S4). Based on this result, determination is made as follows.

That is, if dT ≦ TA, it is determined that the ink ejection is normal (step S6). Also, dT ≧ T
B, it is determined that the ink ejection is abnormal (step S
5).

As the predetermined electric energy causing the ink ejection, for example, a pulse having an ON time of 7 μsec and a frequency of 4 KHz as shown in FIG.
It is conceivable to apply 1000 pulses to all 64 nozzles, and this electric energy is defined as E1. In this case, T
The values of A and TB were about 14.5 degrees and 15.5 degrees, respectively.

The first method described above statistically determines a threshold value for determining whether the head is in a normal ejection state or in an ejection failure state with respect to the variation in the amount of heat generation and outflow from head to head. However, the variation in the temperature characteristics between the head cartridges is large, and
When the maximum value of dTA becomes larger than the minimum value of dTB as shown in FIG. 7B, the above method cannot be applied when TA> TB. . The causes of temperature characteristic variations are:
Variations in the thickness of the adhesive between the heater board 110 and the base plate 130, the resistance value of the discharge heater 111, the dimensions of the heater board and the base plate, and the physical characteristics of the material are considered. Further, when ink is ejected, it is considered that the temperature characteristic varies due to a change in the amount of heat released by the ink due to a change in the size of the ink droplet or the physical properties of the ink.

Next, a description will be given of a second method which can be applied to a case where the temperature characteristics between head cartridges vary greatly. The second method is to detect a temperature characteristic of each head and determine a threshold value for judging an ejection state according to the temperature characteristic.

As described with reference to FIG. 6, even if the temperature characteristics vary from print head to print head, the relationship of dTB> dTA is satisfied for all of the head cartridges. Based on the partial data, dTB-d
The value of TA is calculated, and its minimum value TD is statistically obtained. Then, for every head cartridge,
The relationship of dTB−dTA ≧ TD can be said to be true. Further, generally, at the time of recording start, the ink filling state of the nozzles and the like is in a normal state by the automatic ejection recovery processing.

FIG. 12 is a flowchart for explaining the second method. First, at the start of recording when the ink filling state of the nozzles and the like is in a normal state, the above-described predetermined electric energy is applied to the ejection heater 111 (step S7), and the temperature change near the heater board 110 is measured. To obtain dTA (step S
8). If it is desired to detect whether or not the ink can be ejected, the predetermined electric energy is applied to the ejection heater 111 (step S9), and the temperature change dT near the heater board 110 is measured (step S1).
0), the determination can be made as follows. That is,
If dT ≦ dTA, it is determined that the ink ejection is normal (step S14). If dT ≧ dTA + TD, it is determined that the ink ejection is abnormal (step S1).
3).

When the predetermined electric energy is E1, the value of TD is about 2 degrees. With the above configuration, a temperature change detected when predetermined electric energy is applied to the heater is defined as a temperature characteristic (thermal characteristic) of the recording head, and ink cannot be ejected based on the characteristic. The threshold value (dTA + TD) for determining this is determined, and it is possible to accurately detect whether or not the ink ejection state is normal according to the threshold value regardless of the characteristics of the recording head.

The second method described above is characterized in that a temperature characteristic which is a characteristic relating to the calorific value of the recording head is detected in advance. According to the second method, when a threshold value for detecting an ejection failure cannot be made common among a plurality of heads due to a variation in temperature characteristics of each print head, the temperature characteristics of the print heads are set in advance. By detecting and determining a threshold value in accordance with the characteristics, it is possible to accurately detect the ejection state irrespective of variations in the characteristics of each print head.

In the second method, the temperature change near the heater board 110 when the predetermined electric energy is applied to the discharge heater 111 is unconditionally set to dTA at the time of starting the recording. At the start time, if the ink filling state of the nozzles or the like is not normal due to some cause, erroneous detection will occur.

Therefore, in order to eliminate this problem, a third method of measuring a reference temperature characteristic which is not related to the ink filling state of the nozzles and the like for each head cartridge and using it as a reference will be described below.

Here, as described with reference to FIG. 6, the cause of the difference in the temperature characteristics depending on the ink filling state of the nozzles and the like is that the ink is ejected and the heat flows out. Therefore, in order to obtain the above-mentioned reference temperature characteristic, it is conceivable to apply low electric energy to the ejection heater so that the ink is not ejected even when the ink filling state of the nozzles and the like is normal.

As the predetermined electric energy that prevents the ink from being ejected even when the ink filling state of the nozzles and the like is normal, for example, a pulse having an ON time of 2 μsec and a frequency of 6 KHz as shown in FIG. It is considered that 3000 pulses are applied to all 64 nozzles, and this electric energy is defined as E2. When the predetermined electric energy E2 is applied to the discharge heater 111, the temperature change near the heater board 110 shows almost the same value regardless of the ink filling state of the nozzles and the like. This is because heat does not flow out because ink is not ejected.

Here, the reference temperature characteristic obtained by applying the electric energy E2 shown in FIG. 8B so that the ink is not ejected even when the ink filling state of the nozzles and the like is normal, and the diagram which causes the ink ejection. Consider the relationship with the temperature characteristic obtained by applying the electric energy E1 of FIG.

FIG. 9 shows the heater board 1 when the above two types of electric energy are applied to the discharge heater 111.
It is a graph which shows the temperature change of 10 vicinity.

Curve A shows the case where the ink is properly filled in the nozzle and the common liquid chamber following it, and normal ink ejection is performed by application of electric energy E1, and curve B shows the case where the same electric energy E1 is applied. This is the case where there is no ink in the nozzle and the common liquid chamber following it in the application. The curve C shows the case where the electric energy E2 is applied, and has almost the same characteristics regardless of the ink filling state as described above. dTA, dTB, and dTC are respective temperature changes.

When these measurements are performed for a large number of head cartridges, the temperature characteristics vary from printhead to printhead, so that the values of dTA, dTB, and dTC will differ for each head cartridge. Has the following relationship. dTA = K1 × dTC (K1 is a constant of each head cartridge) dTB = K2 × dTC (K2 is a constant of each head cartridge) K1 <K2 That is, if the constants K1 and K2 are known, the temperature change dTC due to the reference temperature characteristic Thus, the temperature changes dTA and dTB related to the presence or absence of the ink can be calculated.

Then, the constants K1 and K2 will be examined.

FIG. 10 shows the values of K1 and K2 in a plurality of head cartridges N0.7 to N12 having large variations in temperature characteristics, for which data was measured in FIG. 7B. As shown in the figure, the maximum value of K1 is K1max, K1
Assuming that the minimum value of 2 is K2min, the relationship of K1max <K2min holds. The above relation holds even in a head cartridge having a large variation in temperature characteristics.
Temperature change based on the temperature characteristics of each head cartridge, d
This is because the values are achieved not by the values of TA, dTB, and dTC but by the ratio of these values in the same head cartridge.

Therefore, by setting a new constant K so as to satisfy K1max <K <K2min (1), the relation of dTA ≦ K × dTC dTB ≧ K × dTC is established for all head cartridges. Will do.

FIG. 13 is a flowchart showing an ink discharge state detecting step based on the above relationship. First, a predetermined electric energy E2 that does not cause ink ejection is applied to the ejection heater (step S15). Next, the temperature change dTC of the recording head is measured (step S16), and a predetermined energy E1 for causing ink ejection is applied to the ejection heater (step S17). The temperature change dT of the recording head at this time is measured (step S18), and is compared with the K × dTC (step S19).
The determination can be made as follows.

That is, if dT ≦ K × dTC, it is determined that the ink ejection is normal (step S20). If dT ≧ K × dTC, it is determined that the ink ejection is abnormal (step S21). As described above, in the third method, energy that does not cause ink to be ejected is applied to the heater, and the temperature change at that time is regarded as a temperature characteristic relating to the amount of heat generated by the recording head or the amount of heat flowing out. By determining a threshold (K × dTC) for judging a discharge failure according to the temperature characteristic,
Even if there is variation in the characteristics of each printhead, a threshold value for accurately detecting the ejection state can be set regardless of the ink filling state of the printhead.

When the predetermined electric energy was E1 and E2, the values of K1max and K2min were about 1.45 and 1.75, respectively, as a result of the experiment. Therefore, in this case, the value of K may be set to, for example, 1.6 so as to satisfy Expression (1).

In each of the ink discharge state detection methods described above, temperature detection by the temperature sensor is performed while electric energy is being applied to the discharge heater.
When detecting the temperature change at the time of applying the energy, the temperature starts dropping sharply after the application of the predetermined energy. Therefore, when the temperature detection is performed a plurality of times after the application of the predetermined energy, a detection error is likely to occur. Therefore, it is preferable to perform temperature detection during energy application.

However, when the energy is applied by the pulse shown in FIG. 8, stable detection is difficult because the temperature rapidly changes when the pulse is turned on, and noise is easily generated in the temperature detection signal. . Therefore, in this embodiment, the temperature detection during the energy application is performed in synchronization with the pulse and when the pulse is turned off. Further, if the temperature detection is performed after the application of the energy, the minute Detection is performed within the time.

Next, referring to FIG. 4, description will be given of the recording / printing processing procedure of the recording apparatus for detecting the temperature characteristics of the recording head described above and detecting the ink ejection state using the temperature characteristics.

First, when the power of the recording apparatus is turned on, the recovery system motor 226 is operated, the recovery system unit is set to the recovery system home position, the cap 222 is retracted, and the carriage 202 is located at a position facing the cap 222. Set to home position. Thereafter, the cap 222 is again brought into contact with the nozzle portion of the print head to wait for a print data signal. When a recording data signal is input, the transport motor 213 is operated to start paper feeding, and a recording medium such as the fed paper is transported to a desired recording head position. After this, the cap 222 is retracted and detached from the nozzle portion of the recording head. After setting the carriage 202 to the home position facing the cap 222, a predetermined preliminary ejection is performed, and the carriage 202 is moved to a desired recording start position. To move.
In the case of the present embodiment, the preliminary ejection is performed before the recording is performed as described above, and even if the predetermined time T seconds have elapsed from the previous preliminary ejection even during the recording, the carriage 2 is discharged.
02 is again moved to the home position and the preliminary ejection is performed.

Thereafter, ink droplets are ejected by an ink ejection signal corresponding to the recording data, and desired recording is performed. When the printing of one page of the printing medium is completed, the printing medium is discharged, and the ink discharge state is detected using the result of detecting the temperature characteristics of the printing head as described above. In the present embodiment, the timing at which the ink ejection state detection is performed is after the printing of one page of the printing medium is completed, and when a series of printing data extends over a plurality of pages, the printing is performed within one page for each page. In this case, it is performed after recording of one page.

Since the ejection of the ink is detected when the ejection state is detected, the ejection is detected at the home position, which is the position facing the cap 222, similarly to the preliminary ejection. FIG.
4 is a flowchart showing this detection step. That is, when the state detection is started, the head cartridge 201 provided with the recording head determines whether or not the cap is facing the cap (Step S22). If not, the carriage is moved until the cap 222 becomes the facing position. (Step S22, Step S24). Step S22
If the head cartridge 201 is not located at the cap-facing position at the step S24, the process proceeds to step S24,
It is determined whether or not No. 2 is not in a position in contact with the ink ejection port forming surface of the recording head. If the cap 222 is in contact with the ink discharge port forming surface, the cap is opened (step S25). The reason why the state is detected without bringing the cap 222 into contact with the ink discharge port forming surface is to prevent the ink or the like discharged and stored in the cap 222 from contacting the discharge port formation surface.

In the ink discharge state detection step, for example, as described above, the energy for causing ink discharge is set to ON.
When a pulse having a frequency of 4 KHz and a pulse of 4 kHz is applied to all 64 nozzles for a period of 7 μsec, an ink amount of about 5 mg is ejected. Therefore, the ink is ejected toward the cap so as not to stain the inside of the recording apparatus with the ink. Further, in the present embodiment, in order to ensure that the ink is contained in the cap, the cap 22 is discarded in advance in order to discard the ink in the cap and the ink in the pump 223 connected to the cap 222.
The pump 223 is driven to perform a suction operation while the nozzle 2 is separated from the discharge port forming surface of the recording head. This operation is performed before and after the above-described ink discharge state detecting step, whereby it is possible to detect the inside of the recording apparatus without soiling the ink.

In this way, the ink discharge state detecting step is performed, and when an abnormal discharge state is detected, an abnormality detection signal is issued, and the signal is used to display a warning message, turn on a light emitting diode, or generate a warning sound generator. Notification means 1004
A warning sound is issued by the user. After the notification of the abnormal discharge state, when the abnormal state of the recording apparatus is released by a user or the like, a predetermined restart operation is performed.

By detecting the ink discharge state after knowing the temperature characteristics of the recording head in this way, it is possible to accurately detect the ink discharge state without providing a special member. Further, in this embodiment, energy is applied to the ink ejection means for detecting the ejection state, and a temperature sensor which can be manufactured simultaneously with the ink ejection means is used for temperature detection. Detection becomes possible.

Further, the above-described second and third methods for detecting the ink discharge state can be applied even if the temperature characteristics of the recording head vary, so that the dimensions of the heater board and the base plate which cause the variation can be reduced. It is easy to control the accuracy of the material and the thickness of the adhesive, etc., and the effect that the manufacturing cost can be reduced, the type of ink, the physical properties of the ink,
There is an effect that the method can be applied even if the size of the ink droplet changes.

Further, the ink ejection state detection is performed at a position facing the ink receiving member such as a cap, and the ink removing operation of the ink receiving member is performed before and after the detection. Accordingly, it is possible to reliably store the ejected ink, and to minimize stains in the recording apparatus.

In the above embodiment, a diode sensor is used as a temperature sensor for temperature detection. However, the temperature sensor of the recording head can be used without being limited to the sensor as long as the temperature can be detected. For example, the temperature may be detected by detecting the resistance value of an electrothermal transducer such as a discharge heater or a heater. Further, the configuration in which the temperature sensor is provided on the heater board is used, but the position at which the temperature sensor is provided is not limited to the above embodiment.

Further, the recording apparatus may be provided with an ink receiving member such as a sponge capable of absorbing and retaining ink separately from the cap 222, and the ink may be ejected to this member for detecting the ink ejection state. . In addition, the discharge state detection result is configured to notify by the notification unit when an abnormality is indicated. However, the detection result may be notified when the discharge state is normal, and the notification of the result may be performed by the recording device or the host device. You may do it.

(Embodiment 2) In the configuration described in Embodiment 1, in order to obtain the temperature characteristics of the recording head, electric energy was applied to the ink ejection heater and the ejection heater was heated. However, the heating means of the recording head for obtaining the temperature characteristics does not need to be limited to the discharge heater. In the present embodiment, another method will be described. As described with reference to FIG. 3, the print head (head cartridge) of the first embodiment includes heaters 112a and 112b for adjusting the temperature of the print head, separately from the discharge heater. Therefore, the temperature characteristics of the recording head can also be detected by applying predetermined electric energy to the heater.

However, since the ink is not ejected even if the heater is heated, the ink ejection state cannot be detected only by the temperature characteristic by the heating of the heater.

In order to detect the ink discharge state when the heater, which is not the ink discharge means, is used as a heating means for obtaining the temperature characteristics of the recording head, the following is performed.

As described in the first embodiment, a difference occurs in the temperature of the recording head depending on whether or not ink is ejected. So, while heating the heater,
The ejection heater may be driven to eject ink. Thus, a change in the temperature of the heater board similar to that of FIG. 6 of the first embodiment can be obtained according to the state of ink filling in the nozzles and the subsequent ink in the common liquid chamber. Therefore, by integrally considering the heating of the heater and the driving of the discharge heater, the method of the first embodiment can be applied in the same manner. At this time, in order to obtain a temperature characteristic that is not related to the ink filling state of the nozzles or the like, it is sufficient to heat only the heater.

In this embodiment, since the discharge heater is used only for discharging ink, it is not necessary to limit the ink discharge means to the heater. Therefore, according to this embodiment, the present invention can be widely applied to an ink jet recording apparatus having a heater other than a heater for discharging ink. As an ink discharge unit that does not use a heater, there is an ink discharge unit that uses an electromechanical transducer, for example, a piezoelectric element. FIG. 15A is a cross-sectional view of the configuration of the nozzle.
301 is a piezoelectric element, 302 is a heater, and 303 is a discharge port. FIG. 3B is a diagram showing the principle of ejection.
The ink is supplied from the left side of the drawing, and when a pulse is applied to the piezoelectric element 301, mechanical distortion occurs and
3 ejects ink.

(Embodiment 3) In the second and third methods described in the first embodiment, a rise in the temperature of the recording head when electric energy is applied to the discharge heater or the heating heater is detected. Then, it was set as a temperature characteristic peculiar to the recording head. However, the measurement of the temperature change is not limited to this, and another method will be described in the present embodiment. The temperature change of the heater board when electric energy is applied to the heater is as shown in FIG. 6, as already described. At this time, after the completion of the application of the electric energy, the temperature of the heater board decreases due to heat radiation. This is shown in FIG. This temperature drop is determined based on the difference between the heater board temperature at the end of the application of the electric energy and the ambient temperature. Therefore, as shown in the figure, the temperature change at the predetermined time dt after the end of the application of the electric energy is represented by dTa, dT
Assuming that b, dTa and dTb have a correlation with temperature changes (temperature rise) dTA and dTB due to application of electric energy. Therefore, if dTa and dTb are measured and considered to correspond to dTA and dTB, the method of the first embodiment can be applied as it is. In addition,
In the present embodiment, the detection of the temperature characteristic of the recording head is performed after the completion of the application of the electric energy to the heater, so that there is no fear of being affected by noise due to the driving of the heater during the detection.
Therefore, there is an advantage that the detection timing can be freely set when the temperature is detected by the temperature sensor.

(Embodiment 4)
Because it uses the physical properties of ink as its ejection principle,
When the physical properties of the ink change, it is affected. A representative example is a change in the ink ejection amount due to the environmental temperature. In general, the relationship between the environmental temperature and the ink ejection amount in the ink jet recording system is such that as the environmental temperature decreases, the ink ejection amount decreases as shown in FIG. This is because the viscosity of the ink increases at low temperatures.

If the change in the ink ejection amount due to the environmental temperature becomes too large, it may be necessary to correct the temperature according to the environmental temperature in the above embodiment. In the present embodiment, this temperature correction will be described.

As described in the first embodiment, the difference in the temperature characteristics is caused by the release of heat due to ink ejection. Therefore, when the ink ejection amount is smaller than usual, the temperature change dTA becomes larger, and conversely, when the ink ejection amount increases, dTA
TA becomes smaller. That is, when the change in the ink ejection amount due to the environmental temperature is large, the change in dTA due to the environmental temperature cannot be ignored.

Therefore, a method will be described in which the value of dTA at the reference temperature is set as a reference so that the value of dTA does not change much from the reference value according to the environmental temperature. To perform the above temperature correction, if the environmental temperature is lower than the reference temperature, the energy applied to the heater should be increased, and if the environmental temperature is higher than the reference temperature, the energy applied to the heater should be reduced. good. Specifically, the dTA data is collected by changing the applied energy for each environmental temperature, and the applied energy at which the optimal dTA value is obtained is determined in accordance with the environmental temperature, and the applied energy to the heater is determined based on this. Just change the energy.

As a method of changing the applied energy, it is conceivable to change the pulse application time, change the number of applied pulses, change the applied voltage, and the like.

A method is also conceivable in which the judgment processing criterion using the detected temperature characteristic (temperature change) is changed according to the environmental temperature without changing the energy applied to the heater.

For example, in the case of the third method of the first embodiment,
Since the value of the constant K1 changes according to the environmental temperature,
A constant K1 may be calculated for each environmental temperature, and an optimal constant K may be determined based on the calculated constant K1.

(Embodiment 5) In the present invention, an application example in which a recording head is provided with a large number of temperature sensors will be described.

In FIG. 18, in a discharge heater array 111 provided on a heater board 110, for example, a temperature sensor 113 for detecting a temperature is provided at a rate of one for each of eight discharge heaters. In the case of the configuration including the discharge heaters, eight temperature sensors 113 are provided on the same heater board. The output dT of each of the eight temperature sensors
1 to dT8 are transmitted to the printer control unit shown in FIG. For each of the input temperature detection results of the temperature sensors, the ink discharge state detecting step described in the first embodiment can determine whether the ink discharge is normal or abnormal.

The temperature detected by each temperature sensor best indicates the temperature in the vicinity of the position where the sensor is disposed. Therefore, if an abnormal ink discharge state is detected based on the result of temperature detection by a certain sensor, the ink discharge means near the corresponding sensor is detected. Can be determined to be a discharge abnormality. In the present embodiment, when a large number of temperature sensors are provided, as shown in the flowchart of FIG. 19, if any one of the temperature change detection values dT1 to dT8 indicates an abnormal state, the notifying means 1004 indicates the abnormal state. Notification is performed.

A description will be given below with reference to FIG. First, in step S26, the temperature change dT _{1 by the first} temperature sensor- _1.
Is measured. Based on this result, in step S27, the temperature is compared as described in the first embodiment, and
If it is determined in step 37 that the ejection state is abnormal, a warning is issued in step S38. If the judgment of the discharge state using the sensor -1 is normal, the process proceeds to step S28, similarly to measure the change in temperature dT ₂ by the sensor 2. Hereinafter, similarly, temperature detection is sequentially performed up to the sensor 8 (steps S28 to S34), and if any one is determined to be abnormal, an abnormality notification is performed. If all are normal, it is determined that the ink discharge state is normal. I do.

As described above, the ink discharge state can be accurately detected by using a large number of temperature sensors. In the present embodiment, the temperature sensors are provided at a ratio of one to eight discharge heaters. However, the present invention is not limited to this configuration. Individual temperature sensors are provided for each discharge heater, and the temperature characteristics of each discharge heater are determined. Detection may be performed to detect the ink ejection state. In the case where at least one of the detection results is abnormal, the abnormality is notified. However, the processing may be arbitrarily set according to the characteristics of the recording head, the configuration of the recording apparatus, and the like. Further, if it is an ink jet recording head having an electrothermal transducer for temperature control or the like separately from the ink discharging means, it can be applied to an ink jet recording head using the above-mentioned electromechanical transducer.

(Embodiment 6) The detection of the ink ejection state according to the present invention is performed after the end of printing for each page during a series of printing operations as described in the first embodiment. Can be variably set.

FIG. 20 is a block diagram of a recording apparatus capable of setting the execution timing. An input unit 1005 for inputting desired timing is shown separately from the keyboard, but the keyboard may also serve as the input unit.

When detecting the ink discharge state, the ink discharge is performed as described above. Therefore, when the ink discharge state is detected, the amount of recordable ink is smaller than when no ink discharge state is detected. Decreases, albeit slightly. Therefore, by enabling the operator to change the timing of the state detection as needed, the amount of ink consumed in the ink state detection can be saved, and the setting can be made even in a short time interval to improve the detection accuracy. It is possible to raise.

FIG. 21 is a flowchart for setting the detection execution timing. As an example, the execution timing interval that can be set in the automatic mode is set to a predetermined number of days (steps S41 and S42) and a time (step S4).
3, step S44), the number of recordings (steps S45 and S46), and the number of characters to be recorded (steps S47 and S48) can be selected, and an execution command is input to the input unit 1005 from the outside as a manual mode. In this case, the detection is performed in the case where it is detected (steps S39 and S40). In addition to the settable predetermined interval, a default interval previously stored in the control unit of the recording apparatus can be set (step S49).

The ink ejection state detection is executed in accordance with the set execution timing and execution interval.

Since the execution timing of the state detection can be set as described above, the consumption of ink by the ink discharge state detection can be saved, and the detection accuracy can be improved. In the present embodiment, the manual mode and the automatic mode performed at a predetermined interval are separately configured. The state detection may be performed manually by inputting an execution command. Further, the present embodiment can be applied to the ink jet recording apparatus regardless of the difference in the ink discharge state detecting means and the difference in the ink discharge means of the mounted recording head.

(Embodiment 7) An ink jet recording apparatus capable of detecting an ink ejection state has a storage means capable of holding a series of recording data. When an abnormality is detected in the state detection, the recording data is stored. A description will be given of a case where the data is retained and further re-recording using the recording data is possible.
FIG. 22 is a block diagram showing an outline of the recording apparatus. 1
Reference numeral 005 denotes an input unit capable of inputting the execution timing of the ink discharge state detection described in the previous embodiment and further capable of inputting an execution start command in the manual mode. 100
6aCb is a memory capable of holding a series of recording data. The memory may be provided in one of the printer unit and the control unit.

First, the detection of the ink discharge state in this embodiment will be described with reference to the flowchart of FIG. As the state detection method, the method already described in the first embodiment is used. However, in order to further improve the detection accuracy, once the discharge abnormality is detected, the discharge state is detected again, and the detection is performed again. An ejection recovery process including an automatic ink suction operation from the recording head (step S59) and a predetermined amount of ink ejection operation are performed before (step S60), and the abnormality is detected again after the first abnormality is detected. When is detected, it is configured to be recognized as abnormality detection.

The discharge recovery processing and the predetermined amount of ink discharge
The first abnormality detection is performed for the purpose of confirming whether or not the abnormality has been detected because the ink of the recording head has been completely consumed. That is, the ink supply may be interrupted due to the generation of bubbles in the ink path in the print head, the breakage of the meniscus at the ink ejection port due to vibration, etc. It is determined whether it is for good.

Before the ink is completely consumed, the ink supply from the ink tank can be recovered by the discharge recovery process including the suction operation (step S59), and the predetermined amount of ink is actually discharged in step S60. If a reliable ink supply is confirmed by performing this operation, a normal state is detected in the ink discharge state detection again. If the abnormality detection indicates that the ink has been exhausted, the ink supply cannot be reliably recovered in the ejection recovery process. Even if a small amount of ink is sucked from the ink tank and guided to the ink discharge means, the ink supply is interrupted again by the next predetermined amount of ink discharge. You.

FIG. 24 shows storage means 1006 for recording data.
The print data is held by using the
4 is a flowchart showing a procedure for preventing loss of data. When an ink ejection abnormality is detected as described above (step S62), a series of print data that has been printed at the time of detection is stored in the storage unit 1006 (step S6).
3). Thereafter, the fact that an abnormality has been detected is notified (step S6).
4) Requesting inspection of the recording head (step S6)
5). When it is detected that the inspection operation has been completed or the recording head has been replaced (step S66), and a re-recording execution instruction is input (step S67), the automatic paper feeder (hereinafter referred to as C) is executed.
It is determined whether or not the printer is mounted on the recording apparatus (step S68). If the printer is mounted, a paper feeding operation is performed (step S69). If the printer is not mounted, a paper feed request message is issued. (Step S70). After confirmation of paper feeding (Yes in step S71)
s), the recording data is read from the storage unit 1006 (step S72), and re-recording is performed based on the recording data (step S73).

In this embodiment, at the time of re-recording, the position of the recording data at which re-recording is started can be designated.
Re-recording is performed from a data position arbitrarily specified according to the location of the recording abnormality. This embodiment is particularly suitable for an output device of a communication device such as a facsimile among recording devices.

In this manner, the detection of the ink discharge state is performed again, and the detection accuracy can be improved by performing the discharge recovery processing including the suction operation and the predetermined ink discharge before the detection is performed again. By holding the print data, it is possible to prevent the print data from being lost due to the ejection abnormality.

In this embodiment, an instruction to end the inspection or replacement of the recording head can be made by inputting an instruction by the user through the input means that the operation has been completed. However, a configuration may be adopted in which the exchange of the recording head and the attachment / detachment from the recording apparatus are automatically detected and performed.

In the present invention, a so-called full-line type recording head can be used in addition to a so-called serial type recording head.

The present invention particularly provides an excellent effect in a recording apparatus using an ink jet recording head which forms flying droplets by utilizing thermal energy and performs recording among ink jet recording systems. .

The typical structure and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, liquid (ink)
At least one drive signal corresponding to recorded information and providing a rapid temperature rise exceeding nucleate boiling is applied to the electrothermal transducer disposed corresponding to the sheet or the liquid path holding the liquid. As a result, heat energy is
This causes film boiling on the heat-acting surface of the recording head, and as a result, it is possible to form bubbles in the liquid (ink) in one-to-one correspondence with the drive signal. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, A configuration using U.S. Pat. No. 4,558,333 or U.S. Pat. No. 4,459,600 which discloses a configuration in which the heat acting portion is arranged in a bending region may be adopted.

In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters.
A configuration based on JP-A-59-138461, which discloses a configuration in which an opening for absorbing the pressure wave described above corresponds to the discharge section.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is determined by combining a plurality of recording heads as disclosed in the above-mentioned specification. This may be either a configuration satisfying the above requirements or a configuration as a single recording head formed integrally.

In addition, by being mounted on the apparatus main body, it is possible to make an electrical connection with the apparatus main body and supply ink from the apparatus main body. Alternatively, a cartridge type recording head provided with an ink tank may be used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like as the configuration of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. Specific examples thereof include capping means for the recording head, cleaning means, pressurizing or sucking means, preheating means using an electrothermal converter or another heating element or a combination thereof, and recording. It is also effective to perform a preparatory ejection mode for performing another ejection in order to perform stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, and the recording head may be integrally formed or a combination of plural recording heads. The device may be provided with at least one of a multi-color color or a full-color color mixture.

In the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens at room temperature, or which is liquid, In general, in the ink jet method, the temperature of the ink itself is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. What is necessary is just to be liquid.

In addition, the temperature rise due to heat energy is positively prevented by using it as energy for changing the state of the ink from the solid state to the liquid state, or the ink is left standing for the purpose of preventing the ink from evaporating. Either using ink that solidifies, or in any case, the ink is liquefied by applying heat energy according to the recording signal, and the ink is ejected as a liquid ink, or the ink that has already started to solidify when it reaches the recording medium. The use of an ink which liquefies for the first time by heat energy, such as described above, is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or Japanese Patent Application Laid-Open No. 60-71260, while being held as a liquid or solid substance in a porous sheet concave portion or through hole so as to face the electrothermal converter. It is good also as a form. 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 to the above, the recording apparatus according to the present invention may be implemented as an image output terminal of an information processing apparatus such as a word processor or a computer as described above, which is provided integrally or separately. A copying apparatus combined with a reader or the like, or a facsimile apparatus having a transmission / reception function may be used.

[0129]

As described above, according to the present invention,
It is possible to detect a temperature characteristic relating to the calorific value of the recording head due to the difference in the calorific value and the heat outflow amount. as a result,
By applying the detected temperature characteristics of the recording head to various uses, it is possible to obtain a result that is not affected by the individual difference of the recording head. In addition, by setting a threshold value for detecting the ejection state of the print head using the detection result of the temperature characteristic, it is possible to accurately detect the ink ejection state. Further, according to the present invention, it is possible to detect an abnormal ink discharge state that may occur before the ink is completely consumed.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an ink jet cartridge according to the present invention.

FIG. 2 is an exploded perspective view of an example of the inkjet cartridge according to the present invention.

FIG. 3 is an explanatory diagram of a recording unit of the ink jet cartridge shown in FIG.

FIG. 4 is a schematic perspective view showing an ink jet recording apparatus according to the present invention.

FIG. 5 is a block diagram of the inkjet recording apparatus according to the first embodiment.

FIG. 6 is a diagram showing a temperature change in the vicinity of a heater board when electric energy is applied to a discharge heater.

FIG. 7 is a diagram illustrating a temperature change amount near a heater board during application of predetermined energy to a discharge heater.

FIG. 8A is a diagram showing an example of an ink discharge condition of electric energy according to the present invention. FIG. 8B is a diagram illustrating an example of a non-discharge condition of electric energy according to the present invention.

FIG. 9 is a diagram showing a temperature change in the vicinity of a heater board when two types of electric energy, an ink discharge condition and an ink non-discharge condition, are applied to a discharge heater.

FIG. 10 is a diagram showing constants obtained when two types of electric energy, an ink discharge condition and an ink non-discharge condition, are applied to a discharge heater.

FIG. 11 is an explanatory diagram of a first ink ejection state detection method described in the first embodiment.

FIG. 12 is an explanatory diagram of a second ink ejection state detection method described in the first embodiment.

FIG. 13 is an explanatory diagram of a third ink ejection state detection method described in the first embodiment.

FIG. 14 is a view for explaining the movement of the recording head described in the first embodiment to the cap-facing position.

FIG. 15 is a diagram illustrating the configuration and ejection principle of a recording head using a piezoelectric element (piezo).

FIG. 16 is a diagram showing temperature changes in the vicinity of a heater board during and after application of electric energy to a discharge heater.

FIG. 17 is a diagram illustrating a relationship between an environmental temperature and an ink ejection amount.

FIG. 18 is an explanatory diagram of a recording head having a number of temperature sensors.

FIG. 19 is a diagram illustrating an example of detection of an ink ejection state in a recording head having a number of temperature sensors.

FIG. 20 is a block control diagram of a recording apparatus according to a sixth embodiment.

FIG. 21 is a diagram illustrating setting of an ink ejection state detection timing provided so as to be settable.

FIG. 22 is a block control diagram of the recording apparatus according to the seventh embodiment.

FIG. 23 is a diagram illustrating the detection of the ink ejection state again and the processing before the detection.

FIG. 24 is a diagram for explaining the operation of the rewritable recording apparatus according to the seventh embodiment.

[Explanation of symbols]

 111a, 1803 electrothermal transducer 113a temperature sensor 1, 201 recording head 1000 MPU 1001 ROM 1002 RAM

Continued on front page (72) Inventor Yoshiyuki Shimamura 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2C056 EB07 EB30 EB40 EC42 FA03

Claims (27)

[Claims] A recording head having an electrothermal transducer for generating thermal energy in response to the application of an electric signal and a discharge port for discharging ink;
In an ink jet recording apparatus that performs recording by discharging ink from a mounted recording head to a recording medium, a temperature detection unit for detecting a temperature of the recording head, and a heat generation amount or heat of each recording head individual. Temperature characteristic detecting means for detecting a temperature characteristic that fluctuates due to a difference in the outflow amount, wherein the temperature characteristic detecting means is configured to perform the electric heating of the recording head in a process different from recording on the recording medium. A predetermined electric signal is applied to the transducer, and the recording head is mounted on the basis of a result of detecting a temperature change of the recording head caused by thermal energy generated by the electrothermal transducer by the application of the electric signal. An ink jet recording apparatus for detecting a temperature characteristic of the recording head. 2. The method according to claim 1, wherein the electrothermal transducer is a heater provided for ink ejection, and the predetermined electric signal applied to the electrothermal transducer is an amount of thermal energy capable of ejecting the ink. 2. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is an electric signal for generating an image. 3. The method according to claim 2, wherein the electrothermal transducer is a heater provided for ink ejection, and the predetermined electric signal applied to the electrothermal transducer is a heat of an amount that does not eject the ink. 2. The ink jet recording apparatus according to claim 1, wherein the signal is an electric signal for generating energy. 4. The method according to claim 1, wherein the electrothermal transducer is a heater provided for ink ejection, and the predetermined electric signal applied to the electrothermal transducer is an amount of ink capable of ejecting ink by the heater. An electrical signal that generates thermal energy;
2. The ink-jet recording apparatus according to claim 1, further comprising two types of electric signals: an electric signal for generating an amount of heat energy in which the ink is not ejected by the heater. 5. The ink jet recording apparatus according to claim 1, wherein the electrothermal converter is a heater provided for a purpose other than for discharging ink. 6. The recording head according to claim 1, wherein the temperature characteristic detecting unit detects the temperature rise of the recording head when the predetermined electric signal is applied to the electrothermal transducer, based on a temperature rise of the recording head detected by the temperature detecting unit. The ink jet recording apparatus according to any one of claims 1 to 5, wherein a temperature characteristic is detected. 7. The recording head according to claim 1, wherein the temperature characteristic detecting unit detects the temperature of the recording head based on a temperature drop of the recording head detected by the temperature detecting unit after applying the predetermined electric signal to the electrothermal transducer. The ink jet recording apparatus according to any one of claims 1 to 5, wherein a temperature characteristic is detected. 8. The ink jet recording apparatus according to claim 1, wherein the predetermined electric signal is a plurality of pulses having a predetermined cycle. 9. The ink jet recording apparatus according to claim 8, wherein the detection of the temperature change of the recording head performed by the temperature detecting means is performed in synchronization with a cycle of the pulse. 10. An atmosphere temperature detecting means for detecting an atmosphere temperature of the recording head, wherein the temperature characteristic detecting means detects a detection result by the temperature detecting means based on an atmosphere temperature detected by the atmosphere temperature detecting means. 2. The ink jet recording apparatus according to claim 1, wherein the temperature characteristic of the ink jet head is detected based on the corrected result. 11. An atmosphere temperature detecting unit for detecting an ambient temperature of the recording head, wherein the temperature characteristic detecting unit detects a temperature characteristic of the recording head based on the ambient temperature detected by the ambient temperature detecting unit. 2. The ink jet recording apparatus according to claim 1, wherein the predetermined electric signal applied to the electrothermal transducer is changed for the purpose. 12. An ink receiving member for receiving ink discharged from a discharge port of the recording head, and an amount of energy capable of discharging ink to the electrothermal transducer for detecting a temperature characteristic of the recording head. And a means for controlling a relative position of the recording head with respect to the ink receiving member so that the recording head and the ink receiving member face each other, wherein the temperature characteristic detecting means comprises: The ink jet recording apparatus according to claim 2, wherein the temperature characteristic is detected by discharging ink to the ink receiving member by an electrothermal transducer. 13. An ink receiving member for receiving ink ejected from an ejection port of the recording head, a unit for removing ink from the ink receiving member, and the electrothermal device for detecting a temperature characteristic of the recording head. Means for operating the ink removing means before or after the energy application, or before or after the energy application, when an amount of energy capable of discharging ink is applied to the converter. 3. The ink jet recording apparatus according to claim 2, wherein the temperature characteristic detecting unit detects the temperature characteristic by discharging ink to the ink receiving member by the electrothermal transducer. . 14. A method for determining a threshold value for judging whether the ink ejection state of the recording head is good or not, based on a temperature characteristic detection result of the recording head by the temperature characteristic detecting means, and determining the recording detected by the temperature detecting means. 14. The ink jet recording apparatus according to claim 1, further comprising a determination unit configured to determine an ink discharge state of the recording head based on a result of comparing a head temperature with the threshold. 15. The ink jet recording apparatus according to claim 14, further comprising a notifying unit for notifying based on a result of the judgment of the ink ejection state by the judgment unit. 16. A print head having a plurality of temperature detecting means, wherein a predetermined number of temperature detecting means detect temperature characteristics of the print head to determine whether or not the ink discharge state is good. 2. The method according to claim 1, wherein
16. The ink jet recording apparatus according to 4 or 15. 17. An image forming apparatus according to claim 17, further comprising: an input unit configured to allow an operator to instruct execution of the detection of the ink discharge state. 15. The method of claim 14, wherein
17. The ink jet recording apparatus according to any one of claims 16 to 16. 18. The method according to claim 18, wherein the input means is capable of inputting a predetermined timing for detecting an ink discharge state, and the ink discharge state detecting means detects the ink discharge state in accordance with the input timing. The ink jet recording apparatus according to claim 17, wherein: 19. When the determination unit detects that the ink ejection state from the recording head is defective,
19. The ink jet recording apparatus according to claim 14, further comprising control means for making a determination on an ink ejection state again. 20. An apparatus according to claim 19, further comprising an ejection recovery processing unit for restoring the ejection of the ink from the recording head, wherein the control unit performs the control when the ejection state of the ink from the recording head is detected to be defective. 20. The ink-jet apparatus according to claim 19, wherein the means controls the ejection recovery processing means to suck the ink from the recording head to perform the ejection recovery processing, and thereafter, determines the ink ejection state again. Recording device. 21. An ink jet printer according to claim 19, further comprising an ejection recovery processing unit for restoring the ejection of the ink from the recording head, wherein the determining unit determines that the ejection state of the ink from the recording head is defective. Controlling the ejection recovery processing means to perform ink ejection recovery processing by sucking ink from the recording head, then ejecting a predetermined amount of ink from the recording head, and then determining the ink ejection state again. 20. The inkjet recording apparatus according to claim 19, wherein the recording is performed. 22. When the judging means judges that the ink ejection state from the recording head is defective, at least the recording data after the previous detection of good ink ejection state.
19. The ink jet recording apparatus according to claim 14, further comprising: a storage unit for storing data. 23. When the determining means determines that the ink ejection state from the recording head is defective, the recording when resuming recording is performed based on the recording data stored in the storage means. 23. The ink jet recording apparatus according to claim 22, further comprising means for indicating data. 24. When the determining means determines that the ink ejection state from the print head is defective, predetermined print data is stored on the basis of the print data stored in the storage means. 23. The image forming apparatus according to claim 22, further comprising means for enabling the recording head to perform recording again.
The inkjet recording apparatus according to any one of the preceding claims. 25. The recording head according to claim 25, wherein the recording head has an electrothermal converter that causes a state change of the ink due to heat and discharges the ink from an ejection port of the recording head based on the state change. 25. The ink jet recording apparatus according to any one of 1 to 24. 26. An ink jet recording head having an electrothermal transducer for generating thermal energy in response to application of an electric signal and an ejection port for ejecting ink, is exchangeably mounted, and said ink jet head is mounted. A method for detecting a temperature characteristic of the ink jet recording head in an ink jet recording apparatus that performs recording by discharging ink from a recording head to a recording medium, wherein the method is performed by attaching to the apparatus in a process different from a recording process. Applying a predetermined electric signal to the electrothermal transducer of the ink jet recording head, and changing the temperature of the ink jet recording head due to thermal energy generated by the electrothermal transducer by applying the predetermined electric signal. Detecting the ink jet recording based on the detected temperature change. Detecting a temperature characteristic of the ink jet recording head, which varies due to a difference in heat generation amount or heat outflow amount for each ink jet recording head. 27. A method according to claim 27, further comprising the step of:
An ejection state determination method for determining an ejection state of an ink jet recording head, comprising: determining a threshold value for judging whether an ink ejection state of the ink jet recording head is good or not, based on a detected temperature characteristic of the ink jet recording head. A temperature of the recording head when an electric signal is applied to the electrothermal transducer at a predetermined timing during a recording operation by the inkjet recording head, based on a result of comparing the threshold value with the temperature of the recording head; A discharge state determination method, wherein the discharge state is determined.