JPH0760996A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To detect more accurately an ambient temperature of a record head by means of a temperature sensor on a control board by providing a means determining a reading timing of a temperature that a temperature detection means detects in response to a combination of a first driving time, a second driving time and a non-driving time counted by a timer means and a correction value of the read value. CONSTITUTION:A correction method of a detection value of a thermistor is so constituted that it is judged whether it is right after a power is switched on and when it is right after that, it is determined that an electric board 6006 of a recorder body has not the heat accumulation. Then, the temperature of the board is read by means of the thermistor 6016 and the detected value is designated as an ambient temperature. When it is not right after that, it is judged whether there is the influence of the heat. That is, first it is judged whether the recording is executed and when it is before the recording, it is determined that the electric board 6006 of the recorder body has not the heat accumulation due to the recording and it is judged that a time enough for reaching a saturation temperature has passed. When it is determined that the enough time has passed, the temperature of the board is read by means of the thermistor 6016, then the amount of saturation temperature is subtracted from the board temperature and the value is designated as the ambient temperature. By the above processing, it is possible to remove the influence due to the heat of heat generating parts.

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 recording a recording liquid (hereinafter also referred to as ink) onto a recording medium, and more particularly to controlling the temperature 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, facsimiles and the like in offices, printers of various recording systems have been provided as information output devices of these devices. Among them, the inkjet recording type printer has low recording noise, is capable of high-quality recording on various recording media, and can be easily downsized. Therefore, it is suitable for so-called personal use in the office. It is suitable. Among such ink jet recording apparatuses, an apparatus utilizing thermal energy converts an electric signal into heat by an electrothermal conversion element in a recording head, 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, the ejection characteristics generally change greatly depending on the temperature of the ink. Therefore, conventionally, the drive pulse given to the electrothermal conversion element is changed or the recording head is heated for heating according to the temperature of the recording head. The heating element is provided and driven according to the temperature of the recording head to control the recording head temperature. As such control, for example, a temperature sensor is provided in the recording head to perform closed-loop temperature control. When the temperature sensor is used as described above, in a so-called serial type recording apparatus in which the recording head moves to perform recording, a flexible wiring or the like is provided to send the output voltage from the temperature sensor to the AD converter of the recording apparatus main body. Since it is used, it is necessary to take measures against noise caused by this wiring.

By the way, the structure for detecting the temperature of the recording head using the temperature sensor as described above causes the cost of the recording apparatus to increase. Therefore, instead of providing a temperature sensor on the recording head, a thermistor as a temperature sensor is provided on the control board of the recording apparatus main body to detect the environmental temperature of the recording head, and an electric power applied to the recording head is supplied based on this environmental temperature change. There has been known a configuration in which the temperature of the print head is presumedly obtained by performing a calculation in consideration of energy, energy discharged by ink ejection, and energy radiated to the outside air. Further, in such a configuration, the thermistor provided on the control board of the recording apparatus main body is affected by the heat-producing components provided on the board. The temperature rise is estimated by controlling the time, and the ambient temperature is obtained by subtracting the temperature rise due to the influence of the heat generating components from the temperature indicated by the thermistor.

In the structure 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, but such management depends on the addition of an electric circuit and arithmetic processing. As the CPU load increases, the cost increases and the throughput decreases.
Therefore, conventionally, the temperature rise amount of the board is estimated only by controlling the energization ON time and the OFF time of the entire control board.

[0006]

However, the heat-generating components on the control board include those that are always energized while the recording apparatus is in use and those that are energized only when certain control is performed. In the above management of the energization on-time and off-time that do not distinguish them, an error may occur depending on the timing of reading the value of the thermistor. For example,
The motor driver generates a considerable amount of heat when driving the motor. In order to prevent this error, if it is attempted to calculate and estimate the temperature rise from the driving condition, the driving of the motor is complicated, and therefore the arithmetic processing becomes complicated.

The present invention has been made in order to solve the above problems, and its purpose is to more accurately detect the ambient temperature of the recording head by using a temperature sensor on the control board of the apparatus main body. Another object of the present invention is to provide an inkjet recording apparatus.

[0008]

Therefore, according to the present invention,
In an inkjet recording apparatus that uses a recording head for ejecting ink and ejects ink from the recording head onto a recording medium to perform recording, the inkjet recording apparatus is provided on a control board of the inkjet recording apparatus and detects the temperature of the board. Temperature detecting means for controlling the recording operation, and a first energizing time for energizing for control accompanied by control of the recording operation in the control board,
Timing means for measuring a second energization time and a non-energization time for energization for control not involving control of the recording operation, and the first energization time, the second energization time and the time counted by the timing means. Depending on the combination of de-energized time,
And a means for determining a reading timing of the temperature detected by the temperature detecting means and a correction value of the reading value.

[0009]

According to the above construction, while the temperature of the control board is not constant due to the control thereof, for example, the heat generated by the heat-generating components on the control board, the temperature reading means ignores the read value of the temperature detecting means such as the thermistor. After that, the detected value of the detecting means can be read and corrected to set the ambient temperature.

[0010]

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

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

In FIG. 1, the recording head IJC integrated with an ink tank can move in the directions of arrows a and b in the figure by transmitting the driving force of the carriage motor 5013 via the lead screw 5004. During this movement, ink droplets are ejected from the recording head IJC onto the recording medium P, whereby recording is performed. The recording medium P is sandwiched between a conveyance roller 5000 and a paper pressing plate 5002 formed by a SUS plate and the conveyance roller 5000.
Are conveyed by being rotated by the drive of the line feed motor 5001. A cap 5022 for covering the ejection port surface of the recording head is provided at the home position of the movement of the recording head IJC, and the cap 5022 is interlocked with the movement of the recording head IJC via the lead screw 5004. You can move forward and backward.

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

In FIG. 2, the control board 6006 is supplied with electric power by the power supply unit 6005. On the control board 6006, a head driver IC 6011 for driving ink ejection of the recording head IJC, a carriage motor driver IC 6010 for driving a carriage motor 5013, and a line feed motor driver IC 600 for driving a line feed motor 5001.
9, interface 6008, DRAM 6015, R
OM6014, MPU6012, gate array 601
3, control panel units 60078 for keys and LEDs are provided respectively. In addition, capacitors, resistors and the like (not shown) are provided on the substrate 6006. A relatively inexpensive thermistor 6016 is provided on the substrate 6006 on which the above-described heat-generating components are present.
The temperature of can be detected. It is needless to say that each processing described below is 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 energization time and the temperature rise of the substrate, showing the data when the saturation temperature is reached by energization and then the energization is turned off.

Further, FIG. 4 shows the elapsed time and the temperature rise when the saturation temperature is reached by energizing the substrate, the recording is started after that, and the temperature rise due to the influence of this recording reaches the saturation temperature and then the recording is stopped. It is a diagram showing the relationship of.

As is clear from these data, the time interval from the start of energization of the substrate until the temperature rise due to energization reaches the saturation temperature, and from the saturation temperature to the complete temperature decrease (temperature increase Is 0 ° C.) and the time interval until the temperature rise due to recording is completely decreased.

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

In FIG. 5, first, it is 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 recording apparatus main body does not store heat, and the thermistor 6016 is checked in step S1005.
The substrate temperature is read by and the temperature is set to the ambient temperature in step S1008.

If it is not immediately after the power is turned on, it is judged whether or not there is an influence of heat due to recording. As for this judgment,
First, in step S1002, it is determined whether or not recording is performed. If the recording is not yet performed, it is considered that the electric substrate of the recording apparatus main body due to recording does not accumulate heat, and step S10 is performed.
Time t sufficient for the electric substrate to reach the saturation temperature at 03
Determine if _SAT has passed. Here, when it is determined that a sufficient time has passed (in FIG. 3), the substrate temperature is read by the thermistor in step S1006,
In step S1007, the saturation temperature is subtracted from the substrate temperature, and in step S1008, this is set as the ambient 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 is determined that the sufficient time t _SAT has not elapsed, the environmental temperature remains set as before. Yes (step S1009).

When it is determined in step S1002 that the recording has been performed, in step S1004, it is determined whether or not there is an influence of heat due to the recording. It is determined whether or not the time t _{SAT has} elapsed (in FIG. 4). If it is determined that the sufficient time has elapsed in this determination, it is considered that the temperature rise has reached the saturation temperature due to energization, and the processing from step S1006 is performed to update the environmental temperature.

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

By performing the processing described above, it is possible to remove the influence of irregular heat of the parts that generate heat by recording.

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

FIG. 6 is a flow chart showing this correction processing, and FIG. 7 is a diagram showing the relationship between the energization time and 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 saturation temperature of the substrate and the saturation temperature of the recording head when the saturation temperature of the substrate is known in advance, and based on this difference, the read value of the thermistor at the saturation temperature of the substrate is calculated. Correction is performed (step S200 in FIG. 6)
6, S2007). This makes it possible to more accurately know the finally estimated printhead temperature based on the corrected read value (environmental temperature). In addition, when the temperature of the electric substrate does not reach the saturation temperature due to energization,
From step S2009 of FIG. 6, the environmental temperature is corrected from the relationship shown in FIG.

(Third Embodiment) This embodiment is a method for correcting the read value of the thermistor corresponding to an ink jet recording apparatus in which the electric power supply to the control board is minimized by a key operation on the control board. After that, the operation with such a key will turn 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 reaching the saturation time 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 amount of input energy.

This embodiment will be described with reference to the flowcharts of FIGS. 8 and 9.

First, when it is determined in step S3001 that the power has just been turned on, the read value of the thermistor is not corrected and is set to the ambient temperature 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), and if the elapsed time is not sufficient, the environmental temperature was previously determined. Is reserved (step S3013). When it is determined that the elapsed time is sufficient for saturation, next, the temperature rise of the power supply board by soft power-on is considered. First, it is determined whether or not the soft power is turned on after the power is turned on (step S
3003) If it is not turned on, it is considered that it is not necessary to consider the temperature rise of the control board due to the soft power-on, and it is considered that it is deviated from the ambient temperature by the saturation temperature due to the temperature rise of the control board due to the normal energization. . Therefore, step S30
The detected value of the thermistor is read at 10 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 soft power-on key operation is being performed, first, in step S3004, the time until the temperature rise of the control substrate by the soft power on reaches the saturation temperature is the soft power. When it is determined whether or not the time has elapsed from the time of turning on, and when it is determined that the time has not elapsed, in step S3005, the soft power is off, and a sufficient time elapses until the thermal influence of the soft power on disappears. If the elapsed time is sufficient, it is sufficient to consider only the saturation temperature due to normal energization, the substrate temperature detected by the thermistor is read (step S3010), and the correction 2 (step S3012) is performed. Perform environmental temperature update (step S
3014). If it is determined in step S3005 that there is still a heat effect due to soft power-on,
The environmental temperature is left unchanged (step S3013).

If it is determined in step S3004 that the rise of the control substrate due to soft power-on has reached the saturation temperature after a sufficient time has passed, the heat generated by recording in steps S3006 and 3007 is the same as in each of the above embodiments. If there is no influence (step S3013), if there is no influence, the control board temperature indicated by the thermistor read in step S3009 is set to the electric board 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 environmental temperature (step S301)
4).

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

(Others) The present invention is provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink, particularly in the ink jet recording system. The present invention brings about excellent effects in a recording head and a recording apparatus of the type in which the state of ink is changed by the heat energy. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

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

In addition, even in the case of the serial type as in the above example, the recording head fixed to the apparatus main body, or the electrical connection with the apparatus main body or the 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 integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add ejection recovery means of the recording head, preliminary auxiliary means, etc. because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping unit, a cleaning unit, a pressure or suction unit for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type or number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying thermal energy such as ink that is liquefied by applying thermal energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the ink jet recording apparatus of the present invention may be used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. It may be a form or the like.

[0045]

As is apparent from the above description, according to the present invention, while the temperature of the control board is not constant due to the control thereof, for example, the heat generated by the heat-generating component on the control board, the temperature detecting means such as the thermistor is operated. It is possible to ignore the read value, read the detection value of the detection means after the temperature is constant, correct this, and set it as the environmental temperature.

As a result, it is possible to more accurately know the temperature environment of the recording head, which allows the recording head to be driven well in accordance with the environmental temperature with a low cost and simple structure, and stable ink can be obtained. Drops are possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration example of an inkjet 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 above apparatus.

FIG. 3 is a diagram showing a temperature rising characteristic of the control board due to energization.

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

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

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

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

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

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

[Explanation of symbols]

 5001 line feed motor 5013 carriage motor 6005 power supply unit 6006 control (electrical) substrate 6007 control panel section 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

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) 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.

Claims (4)

[Claims] 1. An inkjet recording apparatus for recording by using a recording head for ejecting ink and ejecting ink from the recording head to a recording medium, the substrate being provided on a control substrate of the inkjet recording apparatus. A temperature detecting means for detecting a temperature in the control circuit, a first energizing time for energizing for control involving control of a recording operation in the control board, and a second energizing for control without controlling the recording operation. Time measuring means for respectively measuring the energized time and the non-energized time, and the temperature detected by the temperature detecting means according to a combination of the first energized time, the second energized time and the non-energized time measured by the time measuring means. An ink jet recording apparatus comprising: means for determining the reading timing of and the correction value of the reading 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 a predetermined time or more. 3. The predetermined time is the time when 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 the recording. The ink jet recording apparatus according to claim 2, wherein a time for which the temperature rise amount is lowered after the temperature rise of the control substrate is saturated is reached. 4. The recording head according to claim 1, wherein the recording head uses the thermal energy to generate bubbles in the ink and ejects the ink in association with the generation of the bubbles. The inkjet recording device according to item 1.