JP3138368B2 - Ink jet recording device - Google Patents

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 performing recording by discharging a recording liquid (hereinafter, also referred to as ink) onto a recording medium, and more particularly to temperature control of a recording head for discharging recording.

[0002]

2. Description of the Related Art In recent years, with the spread of personal computers, word processors, facsimile machines and the like in offices, printers of various recording systems have been provided as information output devices for these devices. Among them, ink jet recording type printers have advantages such as low recording noise, high quality recording on various types of recording media, and easy downsizing, so that they are suitable for so-called personal use in offices. It is suitable. Among such ink jet recording apparatuses, an apparatus utilizing thermal energy converts an electric signal into heat in a recording head by an electrothermal conversion element, thereby causing film boiling in the ink, and reducing the pressure of bubbles generated by the boiling. It is used to eject ink, and is rapidly spreading.

In the ink jet recording method, since the ejection characteristics generally vary greatly depending on the temperature of the ink, conventionally, the driving pulse applied to the electrothermal conversion element is changed according to the temperature of the recording head, or the recording head is heated. The recording head temperature is controlled by providing a heating element and driving it according to the temperature of the recording head. As such control, for example, there is a method in which a temperature sensor is provided in a print head to perform closed-loop temperature control. In the case where a temperature sensor is used as described above, in a so-called serial type recording apparatus in which a recording head moves and performs recording, a flexible wiring or the like is used to send an output voltage from the temperature sensor to an AD converter of the recording apparatus main body. Therefore, it is necessary to take measures against noise caused by the wiring.

[0004] Incidentally, the configuration for detecting the print head temperature using the above-described temperature sensor causes an increase in the cost of the printing apparatus. For this reason, instead of providing a temperature sensor in the print head, a thermistor, for example, is provided as a temperature sensor on a control board of the printing apparatus main body to detect the environmental temperature of the print head. A configuration in which the temperature of the print head is presumably obtained by performing an operation in consideration of energy, energy discharged by ink discharge, and energy radiated to the outside air has been conventionally known. In such a configuration, the thermistor provided on the control board of the printing apparatus main body is affected by the heat-generating components provided on the board. The temperature rise of the substrate is estimated by managing the time, and the environmental temperature is obtained by subtracting the temperature rise caused by the above-mentioned heat-generating components from the temperature indicated by the thermistor.

In the configuration in which the temperature sensor is provided on the control board as described above, it is originally necessary to manage many driving conditions to estimate the temperature rise. Such management is performed by adding an electric circuit and performing arithmetic processing. This leads to an increase in cost and a decrease in throughput with an increase in the load on the CPU.
Therefore, conventionally, the temperature rise of the substrate is estimated only by managing the power-on time and the power-off time of the entire control substrate.

[0006]

However, there are two types of heat-generating components on the control board: those which are always energized while using the printing apparatus, and those which are energized only when a certain control is performed. In the above-described management of the energization ON time and the OFF time without distinguishing between them, an error may occur depending on the timing of reading the value of the thermistor. For example,
A motor driver generates considerable heat when driving a motor. If it is attempted to calculate and estimate the temperature rise from the driving conditions in order to prevent this error, the driving of the motor is complicated, so that there is a problem that the arithmetic processing becomes considerably complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to more accurately detect the environmental temperature of a recording head by using a temperature sensor on a control board of an apparatus main body. Another object of the present invention is to provide a simple ink jet recording apparatus.

[0008]

According to the present invention, there is provided:
An ink jet recording apparatus that uses a recording head for discharging ink and discharges ink from the recording head to a recording medium to perform recording is provided on a control substrate of the inkjet recording apparatus, and detects a temperature on the substrate. A first power supply time for supplying power for control involving control of a recording operation on the control substrate;
A timer means for measuring a second energizing time and a non-energizing time for energizing for control without controlling the recording operation; and the first energizing time, the second energizing time, and the Depending on the combination of de-energization time,
Means for determining a temperature reading timing detected by the temperature detecting means and a correction value of the read value.

[0009]

According to the above arrangement, the value read by the temperature detecting means such as a thermistor is ignored while the temperature is not constant until the control board controls the temperature, for example, due to the heat generated by the heat-generating components on the control board. After that, the detection value of the detection means is read, and this can be corrected to set the ambient temperature.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a schematic perspective view of an ink jet recording apparatus according to one embodiment of the present invention.

In FIG. 1, a recording head IJC integrated with an ink tank can move in the directions of arrows a and b in FIG. 1 when the driving force of a carriage motor 5013 is transmitted via a lead screw 5004. During this movement, ink droplets are ejected from the recording head IJC onto the recording medium P, thereby performing recording. The recording medium P is sandwiched between a transport roller 5000 and a paper pressing plate 5002 formed of a SUS plate or the like, and the transport roller 5000
Is driven by the rotation of the line feed motor 5001 to be conveyed. A cap 5022 or the like for covering the ejection opening surface of the recording head is provided at a home position in the movement of the recording head IJC. The cap 5022 is interlocked with the movement of the recording head IJC via the lead screw 5004. Can move forward and backward.

FIG. 2 is a schematic diagram showing the electrical configuration of the ink jet recording apparatus.

In FIG. 2, power is supplied to a control board 6006 by a power supply unit 6005. A head driver IC 6011 for driving ink ejection of the print head IJC, a carriage motor driver IC 6010 for driving the carriage motor 5013, and a line feed motor driver IC 600 for driving the line feed motor 5001 are provided on the control board 6006.
9, interface 6008, DRAM 6015, R
OM6014, MPU6012, gate array 601
3, a control panel unit 60078 for keys and LEDs is provided. In addition, a capacitor, a resistor, and the like (not shown) are also provided on the substrate 6006. A relatively inexpensive thermistor 6016 is provided on the substrate 6006 where each of the above-mentioned heat-generating components is present.
Temperature can be detected. It is needless to say that the following processes are mainly executed by the MPU 6012.

Next, a method of correcting the detection value of the thermistor, which facilitates the present invention, will be described.

FIG. 3 is a diagram showing the relationship between the energizing time of the substrate and the temperature rise, showing data when the saturation temperature is reached by energizing and then the energizing is turned off.

FIG. 4 shows the elapsed time and the temperature increase when the saturation temperature is reached by energizing the substrate, recording is started after that, and the recording is stopped after the temperature rise due to the influence of the recording temperature reaches the saturation temperature. FIG.

As is apparent from these data, the time interval from the start of energization to the substrate until the temperature rise due to energization reaches the saturation temperature, and the time interval from when the saturation temperature is reached to when the temperature is completely decreased (temperature increase) Is substantially equal to the time interval of 0 ° C.) and the time interval until the temperature rise by recording is completely lowered.

FIG. 5 shows a flowchart of a method for correcting the thermistor detection value according to the present embodiment using this time interval as t _SAT .

In FIG. 5, it is first determined whether or not the power has just been turned on (step S1001). If the power has just been turned on, it is considered that the electric board (control board) of the printing apparatus main body is not storing heat.
To read the substrate temperature, and set it as the environmental temperature in step S1008.

If it is not immediately after the power is turned on, it is determined whether or not the recording is affected by heat. As a judgment,
First, it is determined in step S1002 whether or not recording has been performed. If recording has not been performed, it is considered that the electric board of the recording apparatus main body is not storing heat due to recording.
03, sufficient time for the electrical substrate to reach saturation temperature t
Determine whether the _SAT has elapsed. Here, if it is determined that a sufficient time has passed (of FIG. 3), the substrate temperature is read by the thermistor in step S1006, and
In step S1007, the saturation temperature is subtracted from the substrate temperature, and in step S1008, this is set as the environmental temperature.

If it is determined in step S1003 that the saturation temperature has not been reached by turning on the power, that is, if it has been determined that the sufficient time t _SAT has not elapsed, the environmental temperature is maintained as previously set. (Step S1009).

If it is determined in step S1002 that the recording has been performed, it is determined in step S1004 whether or not the recording is affected by heat. It is determined whether or not the time t _SAT (FIG. 4) elapses. If it is determined that a sufficient time has elapsed in this determination, it is considered that the temperature rise has reached the saturation temperature due to energization, and the process from step S1006 is performed to update the environmental temperature.

If it is determined in step S1004 that the influence of heat due to recording is still present, that is, if it is determined that not much time has elapsed since the recording was stopped (FIG. 4), the environmental temperature is set previously. (Step S1009).

By performing the above-described processing, it is possible to remove the influence of irregular heat of a component that generates heat by recording.

(Second Embodiment) When the temperature rise of the electric board is large, the temperature rise of the recording head due to the influence of the heat cannot be ignored. The present embodiment is a method for correcting the read value of the thermistor in this case.

FIG. 6 is a flowchart showing this correction processing, and FIG. 7 is a diagram showing the relationship between the energization time, the temperature rise of the electric substrate, and the temperature rise of the recording head.

From the relationship shown in FIG. 7, the difference between the substrate saturation temperature and the recording head saturation temperature when the substrate has reached the saturation temperature is known in advance, and the thermistor reading at the substrate saturation temperature is determined based on this difference. Correction is performed (Step S200 in FIG. 6)
6, S2007). As a result, it is possible to more accurately know the print head temperature that is finally estimated based on the corrected read value (environment temperature). When the temperature of the electric board has not reached the saturation temperature due to energization, FIG.
In step S2009 in FIG. 6, the environmental temperature is corrected by the amount of temperature rise of the print head, which is determined in advance based on the relationship shown in FIG.

(Third Embodiment) This embodiment is a method for correcting a thermistor read value corresponding to an ink jet recording apparatus in which the supply of electricity to a control board is minimized by a key operation on the board. The operation with such a key is hereinafter referred to as turning on / off the soft power.

The relationship between the time required to reach the saturation temperature of the electric substrate described with reference to FIGS. 3 and 4 and the time required to completely cool the temperature after the saturation time has been reached is as follows. It is almost the same as when the power is turned on. This is because the thermal time constant of the control board itself does not depend on the magnitude of the input energy.

This embodiment will be described with reference to the flowcharts of FIGS.

First, if it is determined in step S3001 that the power has just been turned on, the read value of the thermistor is used as the environmental temperature without correcting the read value of the thermistor as in the above-described embodiments (steps S3008 and S3014). Next, it is determined whether or not the elapsed time from the start of energization is the time until the temperature rise of the control substrate reaches the saturation temperature (step S3002). If the elapsed time is not sufficient, the environmental temperature is determined before. (Step S3013). If it is determined that the elapsed time is sufficient for the saturation, next, consider raising the temperature of the power supply substrate by soft power-on. First, it is determined whether the soft power is turned on after the power is turned on (Step S).
3003) When it is not turned on, it is considered that the temperature rise of the control board due to soft power-on does not need to be considered, and it is considered that the temperature is shifted from the ambient temperature by the saturation temperature due to the temperature rise of the control board due to normal energization. . Therefore, step S30
In step S301, the detection value of the thermistor is read, and the saturation temperature of the control board due to normal energization is corrected (step S301).
2. Hereinafter, this correction is referred to as correction 2.)

If it is determined in step S3003 that the key operation of turning on the soft power is being performed, first, in step S3004, the time until the temperature rise of the control board by the soft power on reaches the saturation temperature is equal to the soft power. It is determined whether or not the time has elapsed since the power-on, and if it is determined that the time has not elapsed, a sufficient time elapses until the soft power is turned off and the thermal effect of the soft power-on is eliminated in step S3005. If the elapsed time is sufficient, it is sufficient to consider only the saturation temperature due to normal energization, read the substrate temperature detected by the thermistor (step S3010), and perform correction 2 (step S3012). To update the environmental temperature (step S
3014). If it is determined in step S3005 that the heat effect still exists due to the soft power-on,
The environmental temperature is left as it is (step S3013).

If it is determined in step S3004 that a sufficient time has elapsed and the rise of the control board due to soft power-on has reached the saturation temperature, the heat generated by recording is determined in steps S3006 and 3007 as in the above-described embodiments. It is determined whether the influence of the thermistor is negligible. If there is an influence, the environmental temperature is kept as it is (step S3013). If there is no influence, the control board temperature indicated by the thermistor read in step S3009 is changed to Only the sum of the saturation temperature and the saturation temperature of the electric board due to the influence of the soft power-on is corrected (step S301).
1) Update as the environmental temperature (step S301)
4).

By the above-described processing, the correction of the substrate temperature rise corresponding to the soft power on / off can be performed, and the same effect as the previous embodiment can be obtained.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration 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 is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. 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 a 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 specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application 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. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

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

It is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are not limited to those provided only for one color ink, for example, and for a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, 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 or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself 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. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not limited to those used as image output terminals of information processing equipment such as computers, copying apparatuses combined with readers and the like, and facsimile apparatuses having a transmission / reception function. It may take a form.

[0045]

As is clear from the above description, according to the present invention, the temperature of the temperature detecting means such as a thermistor or the like is maintained until the temperature of the control board is not constant due to the heat generated by the heat-generating components on the control board. The read value is ignored, and the detected value of the detecting means is read after the temperature has become constant, and this can be corrected and set as the environmental temperature.

As a result, it is possible to more accurately know the temperature environment of the recording head, whereby it is possible to drive the recording head satisfactorily in accordance with the environmental temperature with a simple and inexpensive configuration, and to obtain a stable ink. Drops are possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one configuration example of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a schematic diagram mainly showing a configuration of a control board in the apparatus.

FIG. 3 is a diagram showing a temperature rise characteristic of the control substrate due to energization.

FIG. 4 is a diagram showing a temperature rise characteristic of a control substrate due to energization and recording.

FIG. 5 is a flowchart illustrating an environmental temperature detection process according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating an environmental temperature detection process according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a temperature rise characteristic of a control substrate and a recording head due to energization.

FIG. 8 is a flowchart illustrating an environmental temperature detection process according to a third embodiment of the present invention.

FIG. 9 is a flowchart illustrating an environmental temperature detection process according to a third embodiment of the present invention.

[Explanation of symbols]

 5001 line feed motor 5013 carriage motor 6005 power supply unit 6006 control (electric) board 6007 control panel unit 6008 interface 6009 line feed motor driver IC 6010 carriage motor driver IC 6011 head driver IC 6012 MPU 6013 gate array 6014 ROM 6015 DRAM 6016 thermistor

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kentaro Yano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kiichiro Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Daigoro Kanematsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-3-293149 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) B41J 2/01 B41J 2/05

Claims (4)

(57) [Claims] 1. An ink jet recording apparatus which uses a recording head for ejecting ink and performs recording by discharging ink from the recording head to a recording medium, wherein the substrate is provided on a control board of the inkjet recording apparatus. Temperature detecting means for detecting the temperature in the control substrate, a first energizing time for energizing for control involving control of the recording operation on the control substrate, and a second energizing time for controlling without control of the recording operation. A clock means for measuring an energization time and a non-energization time, respectively, a temperature detected by the temperature detection means according to a combination of the first energization time, the second energization time and the non-energization time measured by the clock means An ink jet recording apparatus, comprising: means for determining a read timing of the image and a correction value of the read value. 2. The ink jet recording apparatus according to claim 1, wherein the correction value is not set to 0 only when the second energization time is equal to or longer than a predetermined time. 3. The predetermined time is a time during which the temperature rise of the control substrate is saturated by energization for control without the recording operation, or after the saturation, by energization for control with recording. 3. The ink-jet recording apparatus according to claim 2, wherein the temperature rise time of the control substrate is decreased after the temperature rise is saturated. 4. The recording head according to claim 1, wherein the recording head uses thermal energy to generate bubbles in the ink, and discharges the ink as the bubbles are generated. 3. The ink jet recording apparatus according to claim 1.