JP2693193B2 - Liquid jet recording device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid jet recording apparatus and a recording head for the recording apparatus, and in particular, an electrothermal converter is used as a discharge energy generating means for recording droplets. It is suitable for application to a liquid jet recording apparatus and a recording head for the recording apparatus.

[Prior Art] In this type of liquid jet recording head, since liquid ejection ports such as orifices for ejecting liquid droplets of recording liquid (ink) can be arranged at high density, high resolution recording is possible. The advantages of IC technology and microfabrication technology that have significantly improved reliability and reliability in recent semiconductor fields are more than sufficient. It can be used, and it is easy to make it long and flat (two-dimensional), so that it is easy to make multi-nozzle and high-density mounting. Moreover, the productivity in mass production is good and the manufacturing cost can be reduced. It is especially noticed as a thing.

With such a reduction in cost, a recording head or a recording head in which the recording head is integrated with an ink tank as an ink supply source (hereinafter, referred to as a head cartridge)
Various types of configurations have been proposed, which are disposable and can be easily attached to and detached from the apparatus main body. according to this,
It becomes possible to easily and promptly deal with a recording head failure and the like, and the ink cartridge can be easily replenished with ink. As a result, maintenance or overhaul as an apparatus can be omitted or simplified.

When such a disposable recording head or head cartridge is mounted on the apparatus main body, it is general that electric connection portions in the form of connectors provided on both sides are connected so that electric connection can be obtained. .
That is, the electrical connection enables transmission of drive signals from the control unit provided on the apparatus main body side to the electrothermal transducer provided on the recording head, and various state signals from the recording head or head cartridge to the control unit. Can be transmitted.

By the way, in a recording head using the liquid jet recording method, non-discharge may occur due to various factors, such as solidification of ink, or mixing of external bubbles in nozzles due to vibration or high-temperature driving of the head. In particular, in the case of using a heating element (hereinafter referred to as a discharge heater) as a discharge energy generating element, the temperature of the head is likely to be high because thermal energy is used for discharging ink. In a normal ejection state, most of the heat is taken away by the ejected ink, and the temperature of the head becomes 50
Although the temperature rises only up to about 60 ° C, if the drive is performed in the state where the non-ejection has occurred due to the above-described factors, all the heat generated by the heater is accumulated in the head, and the head temperature may reach 150 ° C or more. Yes, the recording head may be damaged.

Therefore, in this type of liquid jet recording apparatus, a temperature detecting element (temperature sensor) is provided in order to detect abnormal temperature rise and prevent such inconvenience.

Further, in the liquid jet recording system, the temperature of the recording liquid is a very important factor. This is because the physical properties of the recording liquid, such as surface tension and viscosity, change depending on the temperature, and the change in the recording liquid changes the discharge amount and supply speed of the recording liquid. Therefore, means for maintaining the recording liquid in an appropriate temperature range is indispensable. Therefore, an appropriate heating means (heat insulation heater) is also provided to perform rapid heating and heat insulation.
In addition, it is preferable to use a temperature sensor.

[Problems to be Solved by the Invention] In order to perform the temperature control as described above with high accuracy and speed, it is preferable that the temperature sensor is disposed near the recording head, particularly near the ejection heater. In the case of the above-described disposable type recording head, it is desirable that the temperature sensor be provided integrally with the recording head in consideration of facilitation of the replacement operation.

However, when such a configuration is adopted, if there is manufacturing variation in the temperature sensor, the characteristics of the temperature sensor will be different for each recording head, and it is not always necessary to perform uniform control using the output of the temperature sensor. It is considered that accurate temperature control cannot be expected.

The present invention has been made in view of the above points, and an object of the present invention is to provide a liquid jet recording apparatus capable of performing accurate temperature detection even if there are variations in temperature sensors. is there.

[Means for Solving the Problems] Therefore, according to the present invention, an ejection port for ejecting a recording liquid and energy provided for the ejection port and used for ejecting the recording liquid are provided. A liquid jet recording apparatus having a recording head having a generating energy generating element, the recording head having a temperature detecting element for detecting the temperature of the recording head is detachable. Determining means for determining the correction value,
Control means for outputting a control signal for controlling the temperature of the recording head according to the correction value determined by the determining means and the detection output of the temperature detecting element.

[Operation] According to the above configuration, the temperature detecting element is arranged on the removable recording head itself, so that the detection operation is less likely to be delayed, and the correction value of the detecting element and the detection output of the detecting element. Since the temperature of the print head is controlled in accordance with the above, variations in the element output of each print head due to variations in the elements of the device on the apparatus are corrected, and the temperature detection accuracy can be improved.

Examples Hereinafter, the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a structural example of a liquid jet recording apparatus (ink jet recording apparatus) according to a first embodiment of the present invention, FIG. 2 is a structural example of its recording head, FIG. 3 (A) and (B) is the second
2 shows a configuration example of a heater board that can be employed as a component of the illustrated recording head.

First, in FIG. 1, reference numeral 14 denotes a head cartridge, which integrally integrates a recording head constituted by using a heater board described later with reference to FIGS. 2 and 3 and an ink tank as an ink supply source. The head cartridge 14 is fixed on the carriage 15 by a pressing member 41, and these can reciprocate in the longitudinal direction along the shaft 21. The ink discharged from the recording head reaches the recording medium 18 whose recording surface is regulated by the platen 19 at a minute interval from the recording head, and forms an image on the recording medium 18.

An ejection signal corresponding to image data is supplied to the recording head from a suitable data supply source via a cable 16 and a terminal 4 (FIG. 3) coupled thereto. One or more (two in the figure) head cartridges can be provided according to the ink color or the like to be used.

In FIG. 1, reference numeral 17 denotes a carriage 15
A carriage motor for scanning along 21 and a wire 22 for transmitting the driving force of the motor 17 to the carriage 15. Reference numeral 20 denotes a recording medium connected to a platen roller 19.
Is a feed motor for transporting the paper. Also, 122
Is a reference temperature sensor which is provided at an appropriate portion of the apparatus main body and serves as a reference for correcting the temperature sensor described later. The reference temperature sensor 122 is arranged at an appropriate portion that is not affected by the temperature rise inside the machine and monitors the ambient temperature.

FIG. 2 is a structural example of the recording head according to this example. Here, reference numeral 1 denotes a heater board, which is formed by forming an electrothermal transducer (discharge heater) 5 and a wiring 6 made of Al or the like for supplying electric power to the silicon substrate by a film forming technique. And
A liquid jet recording head is configured by bonding a top plate 30 provided with a partition wall for forming a liquid passage (nozzle) 25 of the recording liquid to the heater board 1.

The recording liquid (ink) is supplied to the supply port 24
The liquid is supplied to the common liquid chamber 23, and is guided into each nozzle 25 from here. When the heater 5 generates heat by energization,
Bubbling occurs in the ink filled in the nozzle 29, and the discharge port 26
That is, more ink droplets are ejected.

3A and 3B are a plan view and a partially enlarged view of a heater board according to the present embodiment, respectively.

In FIG. 1A, reference numeral 3 denotes a discharge heater section. A terminal 4 is connected to the outside by wire bonding. Reference numeral 2 denotes a temperature sensor serving as a temperature detecting means, which is formed on the discharge heater unit 3 by the same film forming process as that of the discharge heater unit 3 and the like. FIG. 2B shows the sensor 2 in FIG.
And FIG. 8 is an enlarged view of a portion B including a heat insulating heater 8 as a heating unit for heating the head. Further, reference numeral 9 is a resistor pattern which is disconnected by a minute current, and is used for the process of determining the timing for determining the correction value of the temperature sensor 2.

Since the sensor 2 is formed by a film forming process similar to that of a semiconductor, like other parts, the sensor 2 has extremely high accuracy.
It can be made of a material whose conductivity changes according to temperature, such as aluminum, titanium, tantalum, tantalum pentoxide, niobium, which are constituent materials of other parts. For example, among these, aluminum is a material that can be used for the electrode, titanium is a material that can be disposed between the heating resistor layer that constitutes the electrothermal transducer, and the electrode to enhance the adhesion between the electrode, and tantalum is a material that can be used for the heating resistor. It is a material that can be placed on top of the protective layer on top of the layer in order to increase the cavitation resistance. Further, the line width is increased in order to reduce process variations, and the resistance is increased in a meandering shape in order to reduce the influence of wiring resistance and the like.

Similarly, the heat insulation heater 8 and the resistor pattern 9 are also provided.
Are made of the same material (for example, Hf
Although it can be formed using B ₂ ), it may be formed using other materials forming the heater board, such as aluminum, tantalum, and titanium.

Next, a mode of temperature control of the recording head according to the present embodiment will be described.

In the recording head shown in FIG. 2 according to this example, the temperature sensors 2 are provided at both ends of the heater board 1 as shown in FIG. 3, so that the substrate temperature in the arrangement direction of the nozzles 25 can be calculated from the outputs of these temperature sensors. The distribution state can be grasped. Further, since the heat retaining heater 8 is provided in the vicinity of the temperature sensor 2, the response speed of detection of temperature change due to heating is high.

However, the process of forming the heater board in the same manner as the semiconductor manufacturing process may include a wet etching process. However, since the etching solution circulates well at both end sides of the discharge heater section 3, the etching easily proceeds and the temperature sensor 2, the output of the temperature sensor 2 may not be stable for each recording head, and it is difficult to accurately detect the temperature.

Therefore, in this example, the correction value of the temperature sensor 2 is determined by using the output of the reference temperature sensor 122, and the output of the temperature sensor 2 is corrected by the correction value in the temperature control for further accuracy.

FIG. 4 (A) shows an outline of a configuration example of the control system according to this example.

Here, 50 is a control unit that forms the main control unit of the apparatus, and is a CP that executes the processing procedure described later with reference to FIGS. 5 and 6.
U, a ROM for storing fixed data such as a program corresponding to the processing procedure and a table of temperature data corresponding to the temperature sensor output, a RAM for storing correction data and the like, and a power supply device for energizing the heater, etc. And so on. In this example, the contents stored in the RAM, especially the correction data, are backed up by a battery or the like so that the contents will not be lost even when the power of the apparatus main body is turned off.

Reference numeral 51 is a recording head incorporated in the disposable type head cartridge described with reference to FIGS. 2 and 3. Reference numeral 54 denotes an ejection recovery device, which is provided outside the recording range in FIG. 1, for example, at a home position of the recording head 51 or the carriage 15 so as to face or be joined to the recording head 51, and to communicate with the cap device. And a suction mechanism for sucking ink from the ink discharge port.

Reference numeral 55 is an alarm device, which can be an indicator such as an LED, a sound generating device such as a buzzer, or a combination thereof. Reference numeral 56 is a main scanning mechanism for scanning the carriage 15 for recording or the like, and includes a motor 17 and the like. 57
Is a sub-scanning mechanism, which includes a motor 20 for conveying a recording medium.

FIG. 4B shows a detailed configuration example of the main part in the above configuration. Here, 51 is a recording head, 8 is a heat retention heater, 2 is a meandering resistor made of aluminum or the like, or a temperature sensor such as a diode, and 10 is a reference power source. Reference numeral 11 denotes an amplifier for forming a constant current source that supplies a constant current to the temperature sensor 2, and the flowing current I _F is It is.

FIG. 5 shows the temperature characteristics of the diode at a constant current. The amplifier 9 at the rear stage of the amplifier 11 in FIG. 4B multiplies the difference between the output V _{A at the} front stage and the reference power source E by R ₅ / R ₄ and the output V _O is Given by

However, these equations (1) and (2) are merely calculated values in the ideal amplifier, and in reality, the offset voltage ΔV exists in the amplifier 9 in FIG. 4 (B), and considering this point, (2 )ceremony Becomes That is, the output V _O is affected by (R ₅ / R ₄ ) · ΔV, that is, the gain times the offset voltage.

When the diode is used as a temperature sensor, the temperature characteristic of the forward voltage drop of the diode is used, but even if the rate of change with temperature is the same as shown in FIG. Variations such as shown occur.

As shown in FIG. 6, when a diode is used as a sensor, the output V _O linearly increases as the temperature rises, and the actual straight line A has a variation of ΔV _O in width. It will be. However, an important point here is that the inclination α of the straight line is determined by the characteristics of the sensor, and this value falls within an accuracy of 1% or less particularly in a semiconductor such as a diode.

Therefore, in the temperature control according to this example, the A / D conversion value of V _{O at} a predetermined temperature is previously stored in the nonvolatile memory 110.
An accurate temperature measurement can be realized by writing the data in a RAM (backed up by a battery or the like) and correcting the temperature sensor 2 based on the data.

FIG. 7 shows an example of a correction value determination processing procedure with the configuration of FIGS. 4 (A) and 4 (B), and this procedure can be started when the power is turned on or when the head cartridge 14 is replaced.

When this procedure is started, first, in step S1, the resistor 9
Conducts electricity to the extent that no disconnection occurs, and whether or not there is continuity (specifically, the digital value corresponding to the analog amount received from the resistor 9 side to the input end A / D 1 in FIG. 4B). Is less than a predetermined value V _F ). Here, if a completely new head cartridge 14 is installed, an affirmative decision is made, and the operation proceeds to step S3.

In step S3, the output of the reference temperature sensor 122 (specifically, the digital value corresponding to the analog amount received by the input end A / D 2 of the reference temperature sensor 122 in FIG. 4B) is read, Specify the ambient temperature T _O. Next, in step S5, the output of the temperature sensor 2 provided on the heater board 1 of the recording head 50 (specifically, corresponding to V _O received at the input terminal A / D 3 in FIG. 4B) The digital value) is read and the temperature data corresponding to the output is determined. Next, define a correction value X _O of the sensor 2 from the temperature data determined from the output of the sensor 22 and the sensor 2 in step S7, which is stored in a predetermined area of the RAM. In this example, one temperature sensor 2 is provided on each side of the heater board 9, so that a correction value is determined for each temperature sensor 2 and the RAM of FIG. 4A, that is, the nonvolatile memory of FIG. Store at 110.

Next, in step S9, a current causing disconnection is passed through the resistor 9 (the output OUT1 is turned on for a predetermined time in FIG. 4 (B)) to cut the pattern. As a result, the processing for determining the correction value for that head cartridge (steps S3 to S7) is not performed thereafter, and the processing speed can be increased accordingly.

FIG. 8 shows an example of a temperature control procedure using the correction value obtained as described above. First, in step S11, the amplifier 9
Output (input of A / D 3) V _O is A / D converted, and in step S13, from this value (value obtained by A / D conversion of the input value of A / D 3),
The A / D value (A / D value) at a predetermined temperature (T _O ) stored in the nonvolatile memory 110 in advance by the process shown in the figure, for example, 25 ° C
Input value of 2) Subtract X _O. This difference is taken as X, and the output variation C [V /
℃] In dividing X, it calculates the actual temperature change from the predetermined temperature (T _O) (step S15). The current temperature T can be obtained by the above steps.

If T is obtained in this way, comparison with the set temperature T ₁ (step S17) can be performed to control ON / OFF of the heat retention heater (step S19). And according to this example,
Such temperature control is performed more accurately.

Next, a case where the aluminum meandering pattern as shown in FIG. 3 is used as a sensor will be described.

The resistance value in this case is determined by the total length and the pattern width, Given by That is, it is proportional to the overall length and inversely proportional to the pattern width. Here, γ is a constant. Therefore, in this example, the pattern for functioning as a sensor may be devised, and L and W may be designed so as to obtain a value that facilitates temperature detection.

FIG. 9 shows the temperature characteristics of aluminum. Unlike a diode, aluminum has a constant current F whose resistance value increases as the temperature rises, so that the voltage drop V _F across both ends increases. In this case, the circuit output V _O is a straight line descending to the right as shown in FIG. 10, but the slope β is constant due to the characteristics of aluminum. Therefore, as in the case of the diode sensor described above, if the A / D conversion value of V _{O at} the predetermined temperature (T _O ) is written in the nonvolatile memory, the circuit error is corrected by the same control procedure as the previous time. Temperature control can be realized.

(Embodiment 2) In the above (Embodiment 1), the correction value determination processing is performed only when the new recording head 51 or the head cartridge 14 is mounted, but the overall processing time is shortened. Such processing may be performed at an appropriate timing during non-recording.

FIG. 11 shows an example of a processing procedure therefor. First, in step S21, the presence or absence of a recording command is determined. If an affirmative determination is made here, the process proceeds to step S23, and the ejection heater 5 group is driven according to the print data to execute the print processing. Further, temperature control as shown in FIG. 8 can be performed in this process.

On the other hand, if a negative determination is made in step S21, the process proceeds to step S25, and a predetermined time (for example, the time until the print head temperature becomes equal to the ambient temperature) has elapsed without performing the print process (step S23). Determine whether or not
If the determination is negative, the process returns to step S21. On the other hand, if an affirmative decision is made, then the flow of control proceeds to a step S27, where the same correction value determination processing as in steps S3 to S7 of FIG. 7 is carried out, and the flow returns to step S21.

According to this procedure, it is possible to deal with the case where the characteristics of the temperature sensor change due to some factor, and there is no problem even when the head cartridge that has been once removed is used again after being used by another cartridge. Become.

Further, by adopting this procedure, it is possible to eliminate the need to dispose the resistor 9, and it is not necessary to back up the correction value in the RAM, which leads to an increase in the price of the recording head and the main body of the apparatus. Nor.

Other Embodiments In the above description, the case where the present invention is applied to the liquid jet recording apparatus in which the head cartridge in which the recording head and the ink tank are integrated is used has been described.
The two may be separate bodies, and the ink tank portion does not necessarily have to be disposable.

The temperature sensor 2 may be in the form of a thermistor or a diode, or may be a transistor or the like. Also,
As described above, it may be formed simultaneously with the discharge heater 5 on the heater board 1, or may be formed separately. Alternatively, the recording head may not necessarily be formed on the heater board 1, and an appropriate number can be provided at an appropriate portion of the recording head.

Further, in the above example, the configuration in which the reference temperature sensor is provided in the main body of the apparatus has been described, but the operator may input the ambient temperature at that time by key input or the like.

In addition, the present invention is not necessarily limited to the above-described serial recording method as long as a disposable recording head or a head cartridge is used.

[Effects of the Invention] As described above, according to the present invention, since the temperature detecting element is arranged on the removable recording head itself, the detection operation is less likely to be delayed, and the correction value of the detecting element is Since the temperature of the recording head is controlled according to the detection output of the detection element, the variation in the element output of each recording head due to the variation of the element on the device is corrected,
The accuracy of temperature detection can be improved.

[Brief description of the drawings]

1 is a perspective view showing a configuration example of an ink jet recording apparatus according to a first embodiment of the present invention, FIG. 2 is a perspective view showing a configuration example of a recording head thereof, and FIGS. 3 (A) and 3 (B). FIG. 4 is a perspective view showing a configuration example of a heater board applicable to the recording head shown in FIG. 2, and FIGS. 4 (A) and 4 (B) are respectively the first embodiment of the present invention.
FIG. 5 is a block diagram showing a schematic configuration example of a control system of a device according to an embodiment and a detailed configuration example of its main part, and FIGS. 5 and 6 show temperature characteristics and circuit output characteristics of a diode that can be used as a temperature sensor. Explanatory drawing shown, FIG. 7 is a flowchart showing an example of the sensor correction value determination processing procedure, FIG. 8 is a flowchart showing an example of the same temperature control procedure, and FIGS. 9 and 10 can be used as a temperature sensor. FIG. 11 is an explanatory view for explaining temperature characteristics and circuit output characteristics of a resistor pattern of aluminum, and FIG. 11 is a flowchart showing an example of a sensor correction value determination processing procedure according to the second embodiment of the present invention. 1 ... Heater board, 2 ... Temperature sensor, 3 ... Discharge heater section, 5 ... Discharge heater, 8 ... Heat retention heater, 9 ... Resistor, 14 ... Head cartridge, 50 ... Control section, 51 …… Recording head, 122 …… Reference temperature sensor.

Claims (5)

(57) [Claims] 1. A recording head having an ejection port for ejecting a recording liquid and an energy generating element which is provided corresponding to the ejection port and generates energy used for ejecting the recording liquid. In a liquid jet recording apparatus in which a recording head having a temperature detection element for detecting the temperature of the recording head is detachable, a determination unit that determines a correction value related to the characteristic of the temperature detection element, and the determination A liquid jet recording apparatus, comprising: a control unit that outputs a control signal for controlling the temperature of the recording head according to the correction value determined by the unit and the detection output of the temperature detection element. . 2. A temperature detecting means for detecting an ambient temperature in the liquid jet recording apparatus, wherein the determining means determines the correction value from the detected output and the output of the temperature detecting element. The liquid jet recording apparatus according to claim 1. 3. The liquid jet recording apparatus according to claim 2, wherein the determining unit makes the determination when the unused recording head is mounted. 4. The recording head according to claim 3, further comprising means for holding information indicating that the recording head is unused, and the determining means destroys the information after the determination. Liquid jet recording device. 5. The liquid jet recording apparatus according to claim 2, wherein the determination unit makes the determination when the recording operation is suspended for a predetermined time.