JPH04211961A - Ink jet recording apparatus and data processing apparatus - Google Patents

Abstract

PURPOSE:To efficiently perform the emission abnormality detection processing and emission recovery processing of an ink jet recording head. CONSTITUTION:Electrothermal converters R1, T2,... are driven by the supply of drive signals S1, S2,... and, when there is the abnormality due to thickened ink or the like not so serious in an ink passage, this abnormality is excluded by the emission of said ink. When a serious abnormal state is generated, the temps. of the electrothermal converters R2, R2,... themselves are raised by the heat generated from said converters R1, R2,... by the application of the drive signals S1, S2,.... As a result, the electrothermal converters R1, R2,... take resistance values different from those obtained when ink is normally emitted. These resistance values are measured by supplying change-over signals (measuring signals) P1, P2,... and the above mentioned abnormal state can be discriminated on the basis of said measured values by a discrimination means.

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 for recording by ejecting ink onto a recording medium such as paper, and various information processing apparatuses having this apparatus as information output means.

0002

2. Description of the Related Art Inkjet recording apparatuses have a number of advantages, such as the fact that the noise generated during recording is negligible and the ability to record on so-called plain paper. There are various ink ejection methods for this inkjet recording apparatus, and devices using these various methods have been put into practical use in recent years.

[0003] Among these discharge methods, for example, Japanese Patent Application Laid-Open No. 54
The ejection method described in Japanese Patent No. 51837 has a different feature from other ejection methods in that thermal energy is applied to ink to obtain a driving force for ink ejection. In other words, in this ejection method, ink subjected to the action of thermal energy causes a rapid volume change due to a change in its state, and the acting force due to this volume change causes the ink to be ejected from the ejection opening at the tip of the recording head. Fly as droplets. These flying ink droplets adhere to the recording medium to perform recording.

A recording head using such an ejection method generally includes an ejection port provided for ejecting ink, and a part that communicates with the ejection port and applies thermal energy to the ink in order to eject the ink. The ink passage has a heat acting part as a part of its configuration, and an electrothermal converter for generating the thermal energy is disposed in the heat acting part of the ink path. This electrothermal converter includes a heating resistance layer and at least one pair of electrodes connected to the heating resistance layer, and the heating resistance layer is connected between these electrodes by an electric signal applied between the pair of electrodes. I get a fever. Generally, in such a recording head, a meniscus is formed near the ejection opening of the ink path due to the balance of forces acting on the ink, such as capillary force and pressure difference. After ejection is performed, the ink path is filled with ink by the force acting on the ink, and a meniscus is again formed near the ejection port.

The recording head configured as described above has several problems as described below.

The first problem is as follows. That is, in order to perform stable ink ejection, the pressure of the ink within the recording head, such as the ink path, must be maintained appropriately. For this reason, it is necessary to maintain the appropriate ink pressure in the ink path by, for example, arranging the recording head and the ink tank storing ink supplied to the recording head via a tube or the like in an appropriate positional relationship in the height direction. Various configurations have been proposed to maintain the size. However, when a shock is applied to the recording head during transportation of the apparatus, or when a cap is used to cover the ejection opening of the recording head to prevent ink moisture from evaporating, pressure fluctuations occur within the cap. The force acting on the ink due to these impacts and pressure fluctuations causes the meniscus of the ink to retreat from the vicinity of the ejection port, which is what is called ink drop. When this ink drop occurs, ink cannot be ejected normally, and due to ink drop, the electrothermal converter repeatedly generates heat even though there is no ink in the area where the heat generated by the electrothermal converter acts. In some cases, the generated heat is not dispersed and may cause damage to the electrothermal converter itself.

A second problem is that of ink thickening. In other words, the viscosity of the ink in the ink path increases due to the evaporation of ink water through the ejection ports of the recording head, etc.
This may result in ejection failure such as a decrease in the amount of ink ejected or non-ejection. Although the above-mentioned ink thickening can be prevented to some extent by the above-mentioned capping, it cannot be completely prevented if the recording head is left in a non-discharging state for a long period of time.

A third problem is that of air bubbles in the ink. In other words, fine air bubbles generated in the ink due to the heat associated with ink ejection, and air bubbles that enter from the outside through ink supply path members such as tubes, become relatively large bubbles over a long period of time, and enter the ink path. If present, these bubbles may cause ejection failure such as a decrease in the amount of deflected ejected ink in the ejection direction.

[0009] In order to eliminate or prevent the first to third problems related to ejection failures described above, ejection recovery processing or the like is performed. This ejection recovery process includes a suction process that uses a suction pump or the like to discharge ink from an ink path or the like from an ejection port, and a so-called idle ejection that performs ink ejection that does not involve recording. Instead of the above-mentioned suction process, a pressure process may be performed in which the ink in the recording head is pressurized from the ink supply path side and the ink is discharged from the ejection ports. Through the suction processing, pressure processing, or dry ejection as described above, thickened ink and air bubbles in the ink path can be removed, and these ejection recovery processes increase the force of the ink in the recording head toward the ejection port side. As a result, the ink meniscus can return to its normal position, and the problem of ink dripping can also be solved.

The above-described ejection recovery and other processes are performed at appropriate timings, such as when the apparatus is powered on or when recording starts. However, at the time when processing such as ejection recovery is performed, abnormalities in the ink path such as the above-mentioned ink drop or thickening do not necessarily occur. Therefore, unnecessary processing such as ejection recovery may be performed, and in this case, not only is ink wasted, but the overall printing speed is reduced due to the time required for this processing.

On the other hand, for example, Japanese Patent Laid-Open No. 61-985
No. 42 describes a configuration that detects the temperature of a recording head and determines whether there is an abnormal state in an ink path or the like based on the detected temperature. According to this configuration, it is possible to perform the ejection recovery process only when there is an abnormal state in the ink path or the like. However, detection of this abnormal state is not performed for each of the plurality of ink paths. Therefore, if an abnormal condition occurs in a relatively small number of ink paths among the plurality of ink paths, this will not be easily reflected as a temperature change in the temperature detection, making it difficult to detect the abnormal condition. be.

[0012] An example of a configuration for solving the problem to be solved is the configuration described in Japanese Unexamined Patent Publication No. 14967/1983. This configuration supplies electrical energy that does not lead to ejection to the electrothermal transducer that generates thermal energy for ejection, thereby causing a temperature change in the ink path. Then, the presence or absence of an abnormal state of the ink path is determined based on the change caused in the electrical energy supplied to the electrothermal converter due to this temperature change. According to this configuration, the abnormal state of each ink path can be determined.

[0013]

[Problem to be Solved by the Invention] However, since the above-mentioned electric energy is not large enough to cause ejection, this electric energy is supplied and causes a temperature change in the ink path, and furthermore, this temperature change causes a It takes a relatively long time to meaningfully detect the changes in electrical energy that occur. For this reason, it takes a long time to detect the abnormal state of the ink path, and since the electrothermal converter is energized for this relatively long time, the heat generated during this time generates many fine bubbles. These bubbles may adversely affect subsequent ejection. In addition, since this abnormal state detection processing is performed independently of the ejection recovery processing,
The time required for this reduces the overall recording speed. Furthermore, a special configuration is required to supply electrical energy that does not lead to discharge, and the circuit configuration may become complicated.

An object of the present invention is to provide an electric signal leading to ink ejection to an electrothermal transducer, detect a predetermined state of the electrothermal transducer at this time, and determine an abnormality in the ink path. An object of the present invention is to provide an inkjet recording device capable of performing ejection recovery processing and an information processing device using the device as an information output means.

[0015]

[Means for Solving the Problems] In order to solve the problem, the present invention provides an inkjet recording apparatus that performs recording by discharging ink onto a recording medium, including a plurality of ejection ports for ejecting ink, and each of the plurality of ejection ports. The recording head has an ink path that communicates with the ejection port and is provided with an electrothermal transducer capable of generating thermal energy for ejecting ink, and a recording head that drives the electrothermal transducer of the printhead to generate ink. a driving means for generating the thermal energy leading to discharge; a measuring means for measuring the resistance value of each electrothermal converter when the driving means drives the electrothermal converter; and a measuring means for measuring the resistance value of each electrothermal converter; The present invention is characterized by comprising: a determining means for determining an abnormal state of the ink path based on a resistance value of the ink path.

[0016]

[Operation] According to the above structure, ink is ejected by driving the electrothermal transducer by the driving means. As a result, if there is ink with less serious viscosity or bubbles in the ink path, these are discharged by this ejection. In addition, if an abnormal condition occurs such as increased viscosity, large bubbles, or ink drop, the heat generated by the electrothermal converter due to the above drive will not be effectively dissipated to others, and the increase the temperature. As a result, the resistance value of the electrothermal transducer takes a value different from that when ink is normally ejected. The measuring means measures this resistance value, and the determining means can determine the abnormal state based on this measured value.

[0017]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the configuration of an inkjet recording apparatus to which the present invention can be applied.

In FIG. 1, a recording paper 63 (a recording medium such as paper or a thin plastic plate) is moved in the direction of arrow A by a pair of paper feed rollers 61 and 62, respectively, which are installed at a predetermined interval in the vertical direction of the apparatus. transported. Along the recording paper 63 between the paper feed rollers 61 and 62,
A pair of guide shafts 64 are provided on the front side thereof, and a carriage 110 that can slide along the guide shafts 64 is provided.
is provided. Further, a recording head unit 101 is mounted on the carriage 110. Thereby, the recording head can move along the recording paper 63 in the direction P in the figure while facing the recording paper 63 with its ink ejection openings.

The recording head unit 101 has a plurality of ink ejection openings (
Hereinafter, a discharge port (hereinafter simply referred to as a discharge port) is provided. While the recording head 101 moves along the recording paper, this ejection port
For example, a distance of about 0.8 mm from the recording paper 63 is maintained. The carriage 110 is driven by a carriage drive motor 68
The recording head is reciprocated in the direction of arrow P via a transmission mechanism including a wire 69 and a pulley extending the wire 69, thereby making it possible to move the recording head.

A flexible cable 67 for power supply and signal transmission is connected between the carriage 110 and the control device of the recording apparatus of this embodiment.

[0022] In the above configuration, during recording, in synchronization with the movement of the carriage 110 in the recording line direction (direction P in the figure), the electric current provided corresponding to each ejection port of the recording head unit 101 is activated. The thermal converter is selectively driven based on recording data, and as a result, flying ink droplets ejected from the ejection ports associated with this drive adhere to the recording paper 63 and dots are recorded.

The recording head unit 101 is located at a home position HP set outside the recording range at a predetermined timing when not recording or during recording. A recovery device 70 is provided at the home position HP, which includes a cap for covering the surface where the ejection ports of the recording head are provided, a pump for sucking ink from the ejection ports through the cap, and the like. . Dry ejection and ink suction, which will be described later in FIG.
This is done by using the recovery device 70 at P.

An ink tank 105 serving as an ink supply source for the recording head unit 101 is disposed at an appropriate location in the apparatus of this embodiment, and a tube 10 for ink communication between the ink tank 105 and the recording head unit 101 is provided.
6 has flexibility to follow the movement of the recording head unit 101.

FIG. 2 shows a detailed example of the structure of the recovery device 70 and recording head unit 101 shown in FIG.

The liquid supply path 2 for introducing ink into the recording head 101H has one end 2a connected to the tube 1.
06 to the ink tank 105, and the other end is connected to the common liquid chamber 3 of the recording head 101H. A plurality of ink passages 4 (three in the figure for simplicity) are provided which communicate with the common liquid chamber 3. At the end of each ink path 4 on the side opposite to the common liquid chamber 3 side, an ejection port is provided to form an opening for ejecting ink. The top plate 6A is formed with a recessed portion for configuring the common liquid chamber 3 and the ink path 4, and the substrate 6B is joined to the top plate 6A. An electrothermal transducer 7 that generates thermal energy for ejection is formed at a portion of the substrate 6B corresponding to each ink path 4.

A drive signal is supplied to the electrothermal converter 7 via a wiring 8, and this wiring 8 is connected to the control device of this embodiment via a flexible cable 67 shown in FIG. The second substrate 9 forms a structural member of this recording head unit 101 by supporting the substrate 6B and others. The plate 10 is provided perpendicularly to the flying direction of ink droplets at the end of the recording head 101H on the ejection port 5 side, and ink or the like enters the joints between the plate 10, the substrate 6B, and the top plate 6A. A sealing material is included to prevent this from happening.

In the figure, 12 is the recovery device 70 shown in FIG.
This is a cap constituting the recording head 101H, and can cover the surface where the ejection ports 5 of the recording head 101H are provided. cap 1
2 and a pump (not shown) are connected via a suction tube 13. As described above, the cap 12 can be moved in the direction of the arrow in FIG. 2 by the unillustrated moving means constituting the recovery device 70 to cover the surface provided with the discharge port. By capping with the cap 12, evaporation of ink water from the ejection port 5 is suppressed and thickening of the ink is prevented. In addition, in this capping state, the internal pressure is applied to the cap by a pump, and ink is sucked from the ejection port 5, thereby removing thickened ink and air bubbles that may cause ejection failure, and refilling the ink as described above. Ejection recovery processing is performed.

FIG. 3 shows an example of the configuration of the main parts of the control system of the ink jet recording apparatus shown in FIG.

The control device 50 supplies drive data for the electrothermal transducer 7 and its control signal to the heat generating section drive circuit 51 configured in the recording head unit 101 based on the information to be recorded. 5. It is a control device that performs processing related to this example device, such as the processing described later with reference to FIG. It can be in the form of a microcomputer with a RAM or the like having a work area. Further, the control device 50 controls the conveyance of the recording paper 63 and the movement of the carriage 110. The drive circuit 51 drives the electrothermal transducer 7 based on the drive data supplied from the control device 50. The resistance measuring circuit 53 measures the resistance value of the electrothermal transducer 7, and the comparing circuit 56 compares the measured value by the resistance measuring circuit 53 with a reference value set by the control device 50.

FIG. 4 is a circuit diagram for explaining the specific circuit configuration of the recording head 101H, the heat generating section drive circuit 51, and the resistance measuring circuit 53.

Here, the plurality of electrothermal transducers 7 formed in the recording head 101H are represented by symbols R1, R2, . Tr1, Tr2, . . . are provided. The transistors Tr1, Tr2, . . . turn on/off the corresponding electrothermal transducers R1, R2, . . . according to the states of the drive signals S1, S2, . . . during recording. The transistors Tr1, Tr2, . . . constitute a resistance measuring circuit 53, and are turned on when switching signals P1, P2, . As a result, the electrothermal converter R1,
It is possible to output measurement outputs A1, A2, . . . according to the resistance values of R2, . AND GATE AN1, AN2,...
respectively input the drive signals S1, S2,... to one input terminal (
switching signals P1, P2, . . . to the measuring circuit are connected to the inverting input terminal).
is received at the other input terminal. This configuration prevents malfunctions during recording, that is, drive transistors Tr1 and Tr.
It is possible to prevent an inconvenience in which the switching signal is energized for some reason and the measurement transistor is also turned on even though a signal to turn on the transistors 2, . . . has been sent.

The generation timing of each signal in the circuit shown in FIG. 4 will be explained with reference to FIGS. 5 and 6.

In this embodiment, the electrothermal converter has the symbol R1.
, R3 . . . and time-division driving is performed by dividing into two blocks each consisting of electrothermal transducers indicated by R2 , R4 . As shown in the timing chart of FIG. 6, first, drive signals S1, S3, etc. corresponding to one block are generated, and these are transmitted to the corresponding transistor Tr1.
, Tr3 . . . as five continuous pulses. As a result, an electric pulse corresponding to this pulse is applied to the electrothermal transducers R1, R3, . . . , and normally, ink is ejected from the respective ejection ports. When a predetermined time t1 has elapsed after these driving signals S1, S3, . . . are supplied, switching signals P1, P3, . This causes switching signals P1, P3... to the electrothermal transducers R1, R3...
At the same time, measurement signals A1, A3, . . . having electrical settings corresponding to the resistance values of the electrothermal transducers R1, R3, . . . at this time are generated. The measurement signals shown in FIG. 6 indicate a signal A3, that is, a case where an abnormal state occurs in the ink path where the electrothermal transducer R3 is formed. That is, if the ink thickens or if there is no ink in the ink path due to the presence of bubbles or ink drop, the electrothermal converter R3
If the heat generated is not dissipated elsewhere and its own temperature increases, and the electrothermal transducer has a characteristic of positive resistance change with temperature as shown in Figure 10, its resistance value increases. . As this resistance value increases, the measurement signal A3 becomes smaller. As a result, the comparator circuit 5 receives the signal D2.
The measurement output A3 inputted to the comparator circuit 63B becomes smaller than the set value, and the output C2 of the comparator circuit 563B becomes "0" level.

When the ejection drive and measurement drive for the first block (R1, R3, . . . ) are completed, the ejection drive and measurement drive for the second block (R2, R4, . . . ) are similarly performed. In this way, the first block and the second block are time-divisionally driven. In this case, as shown in FIG. 5, data selectors 561A, 561B... are used to switch measurement signals A1 and A2, A3 and A4...
, P2 . . . According to this, the number of comparison circuits connected after the data selector and the configuration of the control device can be simplified. The control device 50 switches the outputs from the comparison circuits 563A and 563B into switching signals P1 and P1.
2. Read and process in synchronization with...

As explained above, the state of the ink path can be known from the measurement signal output corresponding to each ink path. That is, when an abnormal state occurs in the ink path, such as when there is no ink due to increased viscosity of the ink, inclusion of air bubbles, or ink drop in the ink path, the output from the comparison circuit becomes "0" level.

As described above, the drive signals S1, S2, etc. are the same as the drive signals used for recording, and if no abnormal condition occurs in the ink path, the ink is supplied with these drive signals. is discharged. Therefore, the process of detecting the abnormal state of the ink path described above can be performed as part of the ejection recovery process, for example, as will be described later with reference to FIG. At this time, the ink ejection caused by the drive signals S1, S2, . Further, if the receding of the meniscus (ink drop) is small, the position of the meniscus can be made normal by this idle ejection. As described above, according to the present invention, since only serious abnormal conditions that cannot be resolved by empty discharge are detected, it is sufficient to perform suction processing in conjunction with the detection of this abnormal condition, thereby eliminating the need to perform unnecessary suction processing. There isn't.

In the above embodiment, the electrothermal converter R1
, R2, . For example, the number of blocks may be any number, and the number of electrothermal converters that one block has can also be determined arbitrarily. Furthermore, the electrothermal transducer may not be divided into blocks, but may be driven individually for abnormality detection.

However, in consideration of the time required for this process, the power supply capacity, etc., it is preferable to apply the time division drive used in recording to the ejection drive and measurement drive according to the present invention. As is well known, this time-division driving is performed by, for example, 12
Eight electrothermal transducers are divided into 16 blocks of eight blocks each, and these blocks are driven in a time-division manner. According to this, the configuration for driving the electrothermal transducer, such as the drive signal generation circuit, can be shared between the drive during recording and the drive during the processing according to the present invention.

If the electrothermal transducers are driven and measured by block driving in this way, it is possible to detect non-ejection of all ink paths in a short time even in a recording head having many electrothermal transducers. can.

FIG. 7 shows an example of a process to which the present invention is applied, which can be activated at any appropriate timing, such as before the start of recording, after recording for a predetermined amount or for a predetermined time, when recording is interrupted, or during standby.

When this processing procedure is started, first, the recording head unit 101 moves to the home position HP, and the ejection port 5 and its vicinity are covered with the cap 12 and isolated from the outside air (step S1).

Next, as described above with reference to FIGS. 4 to 6, a plurality of ejection ports in a predetermined block are selected using the drive signal Sk (step S3), and a predetermined number of ejection ports are selected for each corresponding heat generating section drive circuit 51. By sending a continuous pulse signal Sk, idle ejection is performed as part of the ejection recovery process. As a result, the electrothermal converter Rk provides thermal energy to the ink (step S5).

[0044] Here, if no abnormal condition has occurred in the ink path, the ink given thermal energy will undergo a state change, causing a rapid volume change, and due to this volume change, it will flow out from the ejection port. Ink droplets are ejected.

However, if the inside of the ink path is not filled with ink due to ink dropping, or if the ink has thickened or bubbles have occurred, even if driving energy is applied to the electrothermal converter Rk, this energy will not be used to eject the ink. Since the electrothermal converter itself is not consumed, it accumulates as heat in the electrothermal converter itself and its vicinity (heat generating part). As a result, as shown in FIG. 8, the temperature of the heat generating section rises rapidly compared to, for example, when the heat generating section is filled with ink, and the saturation temperature also becomes high.

In this case, as shown in FIG. 9 or 10, the electrical resistance value of the electrothermal converter decreases or increases as the temperature of the heat generating section increases. The reason why there are two types of characteristics of an electrothermal converter with respect to temperature changes is that the characteristics differ depending on the material used to form the electrothermal converter. In this specification, a case will be described in which an electrothermal converter having the characteristics shown in FIG. 10 is used. Note that it is clear that the essence of the present invention does not change even if an electrothermal converter having the characteristics shown in FIG. 9 is used.

Next, as described above with reference to FIGS. 4 to 6, the discharge drive is switched to the resistance value measurement drive by the switching signal Pk, and the change in the resistance value of the electrothermal transducer Rk is measured by the measurement signal A.
k (step S7). Then, this measurement signal Ak is compared with a predetermined reference value, that is, a value when no abnormal condition occurs in the ink path,
Based on the output Ck of this comparison result, it is determined whether or not an abnormal condition occurs in the ink path (step S9).

[0048] If abnormal conditions occur, discharge recovery processing using suction processing is performed to eliminate these conditions (
Step S15). That is, new ink can be easily introduced into all the ink paths in the recording head by activating the pump in the inkjet recording apparatus to create negative pressure in the cap 12 and discharging ink from the ejection ports. In addition, such a recovery operation is performed a predetermined number of times (for example, 3 times).
If no improvement is seen even after repeated attempts, this is reported as an abnormality (step S13).

By carrying out the above operation for all the ejection ports (step S11), it is possible to judge whether each ink path is in an abnormal state, and refill the ink by suction only when it is judged necessary. Therefore, an inkjet recording device with stable operation can be provided without wasting ink.

As described above, according to this example, the following effects can be obtained.

(1) Since the suction process is performed only when it is truly necessary, the amount of ink that is wasted is reduced, and the amount of ink consumption is reduced.

(2) The recovery process is automatically performed until the abnormal state of all ink paths is cleared, eliminating the troublesome work of repeating the recovery process while checking the recording status by the operator. time is reduced.

(3) Since the resistance value of the electrothermal transducer is measured, disconnections and short circuits in the heat generating part can also be detected.

FIG. 11 shows an example of a processing procedure according to another embodiment of the present invention.

The resistance value changes before and after applying electrical energy for ejection, and this example focuses on the fact that the amount of change differs depending on the presence or absence of an abnormal condition in the ink path. . Therefore, in this example, step S2 is inserted between steps S1 and S3, and it is determined whether or not the resistance value (initial resistance value) is measured before the ejection energy is applied. If the judgment is negative, measure the initial value for all discharge ports (
After steps S21, S23, S25), the resistance value after application of ejection energy is determined. Based on the difference between the two resistance values, it is possible to know whether there is an abnormal condition in the ink path (step S9').

[0056] This example also provides the same effect as the above example, but in this example, the presence or absence of an abnormal state is determined based on the amount of change in resistance value in response to temperature change, so it is less susceptible to the effects of environmental temperature. There are advantages.

FIG. 12 shows a processing procedure according to yet another embodiment of the present invention.

The processing procedure shown in FIG. 7 can be started at an appropriate timing, but it can also be executed, for example, when recording is temporarily interrupted in the course of a series of recording processes (at the time of a line feed in a serial printer, etc.). . In this example, this is done at the line feed (line change).

That is, in this example, after the recording operation is performed in step S31, it is determined whether or not there is a line change (step S31).
33), if the determination is affirmative, the steps include testing whether or not an abnormal state has occurred in the ink path (steps S3 to S15).
). The above procedure is then repeated until the series of recording processes is completed (step S35). In this example, the idle ejection (step S5) which also serves as abnormality detection is performed at the time of line change.
) is not performed inside the cap as in the above example, but is performed on an ink absorber or the like (not shown in FIG. 1) provided at a predetermined location outside the recording area. Furthermore, before performing the recording operation in step S31, a recording preparation operation such as removing the cap is performed.

According to this example, it is possible to prevent problems caused by the timing of ejection recovery being missed during a series of recording processes and the drive signal being sent without ejection being performed.

Furthermore, by detecting ejection failure when recording is interrupted as in this example, it is possible to perform reliable printing without ejection failure without increasing the overall recording time.

Furthermore, in this example as well, non-ejection detection can be performed without changing the driving method by using the usual method of driving the electrothermal transducer.

[0063] It goes without saying that the present invention is not limited to the above-described embodiments, and can take various configurations. For example, a device that performs ejection recovery by refilling with liquid (ink) may be configured to suck ink from a predetermined range of ejection ports instead of all the ejection ports at once. According to this, ink consumption can be further reduced. Further, in addition to such suction, it may be performed by pressurizing the ink supply system. Furthermore, even in the case of so-called idle ejection, it is possible to perform ejection recovery processing if the number of ejections and the like are taken into consideration. Accordingly, recovery processing can be performed only for the ink path in an abnormal state.

FIGS. 13, 14 and 15 show other embodiments of the circuit configurations shown in FIGS. 4-6. The switching signal Pk and the AND gate ANk in the embodiments shown in FIGS. 4 to 6 are made common to each block. That is, when driving the electrothermal transducer RK to measure the resistance value, the switching signal for each block can be made common, so for example, when the electrothermal transducer is divided into two blocks and driven in a time division It can be simplified to only two types of switching signals. 13 to 15, the electrothermal converter R is driven using the same timing chart as shown in the embodiment shown in FIGS.
3 shows a case where there is an abnormality in the ink.

FIGS. 16-18 show still other embodiments of the circuit configurations shown in FIGS. 4-6. This circuit is shown in Figures 4 to 6.
In this embodiment, the resistor γ for detecting the measurement signal and the output terminal of the measurement signal are made common. This is because the electrothermal transducers R1 and R2, . . . or R3 and R4, . . . are not driven for measurement at the same time because their driving blocks are different. Therefore, the detection resistor γ and the output terminal of the measurement signal Ak can be shared,
The circuit configuration can be simplified. Furthermore, the data selector can also be omitted. (Others) In particular, the present invention is an inkjet recording method that includes a means (for example, an electrothermal converter, a laser beam, etc.) for generating thermal energy as energy used for ejecting ink, This provides excellent effects in recording heads and recording apparatuses that use energy to cause changes in the state of ink. This is because such a system can achieve higher recording density and higher definition.

For its typical configuration and principle, see, for example, US Pat. Nos. 4,723,129 and 4,740.
Preferably, it is carried out using the basic principles disclosed in the '796 specification. This method is the so-called on-demand type.
It is applicable to both continuous types, but in particular, in the case of on-demand type, it is applicable to the electrothermal converter placed corresponding to the sheet holding the liquid (ink) or the liquid path. , by applying at least one drive signal that corresponds to recorded information and provides a rapid temperature rise exceeding nucleate boiling, the electrothermal transducer generates thermal energy to produce film boiling on the thermally active surface of the recording head. liquid (ink) that corresponds one-to-one to this drive signal.
This is effective because it can form air bubbles inside. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, making it possible to eject liquid (ink) with particularly excellent responsiveness. This pulse-shaped drive signal is described in US Pat. No. 4,463,359 and US Pat.
345262 are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

[0067] In addition to the configuration of the recording head that is a combination of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44 disclose a configuration in which a heat acting part is arranged in a bending region.
A configuration using the specification of No. 59600 is also included in the present invention. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The effects of the present invention are also effective even with a configuration based on Japanese Patent Application Laid-open No. 138461/1985 which discloses a configuration corresponding to the discharge section. That is, regardless of the form of the recording head, according to the present invention, recording can be performed reliably and efficiently.

Furthermore, 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 that can be recorded by a recording apparatus. Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally.

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

Further, it is preferable to add a recovery means for the recording head, a preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention because the effects of the present invention can be further stabilized. . Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

Regarding the type and number of recording heads to be mounted, for example, in addition to a single head that corresponds to a single color ink, there are also systems that correspond to multiple inks of different recording colors and densities. A plurality of them may be provided. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode for only a mainstream color such as black, but may also be a recording mode in which the recording head is configured integrally or in a combination of multiple colors, The present invention is also extremely effective for devices equipped with at least one full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid, but the ink that solidifies at room temperature or lower, and that softens or liquefies at room temperature, or the inkjet method. In general, the temperature of the ink itself is adjusted within the range of 30°C to 70°C to keep the viscosity of the ink within the stable ejection range. Any eggplant is fine. In addition, the temperature increase caused by thermal energy can be actively prevented by using the energy to change the state of the ink from a solid state to a liquid state, or ink that solidifies when left standing is used to prevent ink evaporation. In any case, the ink is liquefied by applying thermal energy in accordance with the recording signal, and the liquid ink is ejected, or the ink has already begun to solidify by the time it reaches the recording medium. The present invention is also applicable when using ink that is liquefied only by energy. The ink used in such cases is disclosed in Japanese Patent Application Laid-Open No. 54-56847 or Japanese Patent Application Laid-Open No. 60-1989.
As described in Japanese Patent No. 71260, the material may be held in a liquid or solid state in a porous sheet recess or through-hole and face an electrothermal converter. In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

In addition, a recording device equipped with a recording mechanism using the liquid jet recording head of the present invention can be used as an image output terminal for information processing equipment such as a workstation, personal computer, host computer, word processor, etc. It may also be used as a copying device combined with a reader or the like, a facsimile device having a transmitting/receiving function, or as an information output means of an optical disk device.

FIG. 19 is a conceptual diagram of a utilization apparatus equipped with an inkjet recording apparatus according to the present invention as information output means.

In FIG. 19, 10000 indicates a device to be used, which can be, for example, a workstation, a personal or host computer, a word processor, a copier, a facsimile, or an optical disk device. Further, 11000 indicates the inkjet recording apparatus shown in FIG. The recording device 11000 is the usage device 1
Based on the control of 0000, processing information is received from the utilization device 10000 and recorded and output in hard copy form.

FIG. 20 is a schematic block diagram showing another embodiment of the portable printer according to the present invention. This can be combined with utilization devices such as workstations, personal computers, host computers, word processors, copying machines, facsimile machines, or optical disk drives.

In FIG. 20, reference numeral 10001 indicates such devices. Reference number 12
000 is a schematically shown portable printer, which is an inkjet recording apparatus (IJRA) 110 shown in FIG.
Built-in 00 and interface circuit 13000
and 14,000. These interface circuits receive information processed by the utilization device 11001 and various control data for controlling the inkjet recording device 11000. The control data also includes handshake control signals and interrupt control signals from the utilization device. Such control signals are those implemented in conventional printer control techniques.

[0078]

As is clear from the above description, according to the present invention, ink is ejected by driving the electrothermal transducer by the driving means. As a result, if there is ink with less serious viscosity or bubbles in the ink path, these are discharged by this ejection. In addition, if an abnormal condition occurs such as a large degree of viscosity increase, bubbles, or ink drop, the heat generated by the electrothermal converter due to the above drive will not be effectively dissipated to others, and the heat generated by the electrothermal converter itself will not be dissipated effectively. Increase temperature. As a result, the resistance value of the electrothermal transducer takes a value different from that when ink is normally ejected. The measuring means measures this resistance value, and the determining means can determine the abnormal state based on this measured value.

As a result, each abnormal state can be detected in each ink path, and the drive of the electrothermal converter for this detection can also be used as the idle ejection drive that is part of the ejection recovery process, making it more efficient. Abnormality detection processing and accompanying ejection recovery processing can be performed.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing a configuration example of an inkjet recording apparatus to which the present invention can be applied.

FIG. 2 is a perspective view showing a detailed configuration example of a recording head and a recovery device according to an embodiment of the present invention.

FIG. 3 is a block diagram showing an example of the configuration of the main part of the control system according to the present example.

FIG. 4 is a circuit diagram showing a specific example of the heat generating unit drive path and resistance measuring circuit shown in FIG. 3;

FIG. 5 is a block diagram of a configuration provided in the control device shown in FIG. 3 corresponding to the resistance measuring circuit.

6 is a timing chart of each signal shown in FIGS. 4 and 5. FIG.

FIG. 7 is a flowchart showing an example of a processing procedure by the control system shown in FIG. 3;

8 is a diagram showing the temperature change of the heat generating section shown in FIG. 3 when a drive signal is applied to the heat generating section; FIG.

FIG. 9 is a diagram showing an example of the relationship between the temperature of the heat generating section and the resistance value of the heat generating section.

FIG. 10 is a diagram showing an example of the relationship between the temperature of the heat generating section and the resistance value of the heat generating section.

FIG. 11 is a flowchart showing a processing procedure according to another embodiment of the present invention.

FIG. 12 is a flowchart showing a processing procedure according to another embodiment of the present invention.

13 is a circuit diagram showing another specific example of the heat generating unit drive path and resistance measuring circuit shown in FIG. 3; FIG.

FIG. 14 is a block diagram of another configuration provided in the control device shown in FIG. 3 corresponding to the resistance measuring circuit.

15 is a timing chart of each signal shown in FIGS. 13 and 14. FIG.

16 is a circuit diagram showing another specific example of the heat generating unit drive path and resistance measuring circuit shown in FIG. 3. FIG.

FIG. 17 is a block diagram of another configuration provided in the control device shown in FIG. 3 corresponding to the resistance measuring circuit.

18 is a timing chart of each signal shown in FIGS. 16 and 17. FIG.

FIG. 19 is a block diagram of an apparatus that uses the inkjet recording apparatus according to the present invention as information output means.

FIG. 20 is a block diagram of a portable printer configured using the inkjet recording device according to the present invention and a device that uses the same as information output means.

[Explanation of symbols]

2 Liquid supply path 3 Liquid chamber 4 Ink path 5 Discharge port 7　Electrothermal converter 12 Cap 13 Suction tube 50 Control device 51 Heat generating part drive circuit 53 Resistance value measurement circuit 56 Comparison circuit 70 Recovery device

Claims (14)

[Claims] 1. An inkjet recording apparatus that performs recording by discharging ink onto a recording medium, comprising: a plurality of ejection ports for ejecting ink; each of the plurality of ejection ports communicates with the ejection port; A recording head having an ink path provided with an electrothermal transducer capable of generating thermal energy for ejecting ink, and driving the electrothermal transducer of the recording head to generate the thermal energy leading to ink ejection. a measuring means for measuring the resistance value of each electrothermal converter when the driving means drives the electrothermal converter; and a measuring means for measuring the resistance value of each electrothermal converter when the driving means drives the ink path An inkjet recording apparatus comprising: a determination means for determining an abnormal state of the inkjet recording apparatus. 2. The driving of the electrothermal converter by the driving means is performed as part of an ejection recovery process in which ink is ejected by the driving and the ink is discharged from the ink path. The inkjet recording device described in . 3. The driving of the electrothermal converter by the driving means and the measurement of the resistance value of the electrothermal converter by the measuring means are performed by moving the heat converter corresponding to each of the plurality of discharge ports to a predetermined position. The inkjet recording apparatus according to claim 1 or 2, wherein the inkjet recording apparatus is characterized in that the recording is performed for each block when divided into a number of blocks. 4. In an inkjet recording apparatus that performs recording by discharging ink onto a recording medium, a plurality of ejection ports for ejecting ink, each of the plurality of ejection ports communicating with the ejection port; A recording head having an ink path provided with an electrothermal transducer capable of generating thermal energy for ejecting ink, and driving the electrothermal transducer of the recording head to generate the thermal energy leading to ink ejection. a measuring means for measuring the resistance value of the electrothermal transducer when the driving means drives the electrothermal transducer; and a measuring means for measuring the resistance value of the electrothermal transducer based on the resistance value measured by the measuring means. An inkjet recording apparatus comprising: a determining means for determining an abnormal state; and an ejection recovery means for discharging ink from the ink path when the determining means determines an abnormal state. 5. The driving of the electrothermal converter by the driving means is performed as part of an ejection recovery process in which ink is ejected by the driving and the ink is discharged from the ink path. The inkjet recording device described in . 6. Driving the electrothermal converter by the driving means and measuring the resistance value of the electrothermal converter by the measuring means move the heat converter corresponding to each of the plurality of discharge ports to a predetermined position. The inkjet recording apparatus according to claim 4 or 5, wherein the inkjet recording apparatus is characterized in that the recording is performed for each block when divided into a number of blocks. 7. The ink jet recording apparatus according to claim 4, wherein the process of discharging the ink by the ejection recovery means is performed by suctioning or pressurizing the ink. 8. A copying device comprising the inkjet recording device according to claim 1 as information output means. 9. A facsimile device comprising the inkjet recording device according to claim 1 as information output means. 10. A word processor comprising the inkjet recording device according to claim 1 as information output means. 11. An optical disc device comprising the inkjet recording device according to claim 1 as information output means. 12. A workstation comprising the inkjet recording device according to claim 1 as information output means. 13. A computer comprising the inkjet recording device according to claim 1 as information output means. 14. A portable printer comprising the inkjet recording device according to claim 1 as information output means.