JP3222629B2 - Ink jet recording apparatus and ink jet recording method - 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 ink onto a recording medium such as paper.
More specifically, the present invention relates to an ink jet recording method and , more particularly, to control of ink temperature in a recording head.

[0002]

2. Description of the Related Art A recording head used in a conventionally known ink jet recording apparatus generally has a plurality of discharge ports, and the size of the opening area of the plurality of discharge ports is generally uniform. On the other hand, when controlling the ink temperature of such a recording head, uniform temperature control is often performed without performing individual temperature control for each of the plurality of ejection ports.

The main purpose of controlling the ink temperature of a recording head is to suppress variations in the density of an image or the like to be recorded by making the ejection amounts of a plurality of ejection ports uniform.

[0004]

However, for the purpose of improving the gradation of a recorded image, a plurality of ejection ports having different ejection ports are provided in one recording head, and the ejection amount is positively increased. There has been proposed a recording medium having different recording densities to enable recording with different densities. In such a print head, when the above-described uniform temperature control is performed, a portion where dark printing is performed, that is, a portion having a large ejection opening area has a relatively large amount of movement of the ink. The ink temperature is lower than in other parts. As a result, a predetermined ejection amount cannot be obtained, and it may not be possible to perform printing at a desired density particularly in relation to a low density portion.

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 use a recording head having a plurality of ink ejection ports having different opening areas. It is an object of the present invention to provide an ink jet recording apparatus and an ink jet recording method capable of performing optimum ink temperature control for each of the different discharge ports.

[0006]

According to the present invention, there is provided:
Using a recording head having a first ink ejection section having an ink ejection port having a first opening area and a second ink ejection section having an ink ejection port having an opening area larger than the first opening area. An ink jet recording apparatus that performs recording by discharging ink from a recording head onto a recording medium, wherein the temperature sensor included in the first ink discharging unit is a temperature sensor of the first ink discharging unit. A first temperature sensor for outputting temperature information, and a temperature sensor included in the second ink ejection unit, the first temperature sensor being for outputting temperature information of ink ejected from the second ink ejection unit. A first heater for heating ink ejected from the first ink ejection unit, a first heater for heating the ink ejected from the first ink ejection unit, and a second ink ejection unit. A second heater for heating ink ejected from the second ink ejection unit, and the first heater based on temperature information from the first and second temperature sensors. And a control unit for performing each of the heating control by the second heater and the heating control by the second heater, wherein the control unit performs the first ink ejection associated with the ink ejection from the first ink ejection unit. Performing heating control by the first heater in accordance with a decrease in the ink temperature of the second ink ejection unit, the decrease in the ink temperature of the second ink ejection unit accompanying the ink ejection from the second ink ejection unit, It is characterized in that heating control by the second heater is performed in response to a temperature drop larger than a drop in the ink temperature of the first ink ejection section. In addition, a recording head having a first ink ejection section having an ink ejection port having a first opening area and a second ink ejection section having an ink ejection port having an opening area larger than the first opening area is used. ,
An ink jet recording method for performing recording by discharging ink from a recording head to a recording medium, wherein the temperature sensor included in the first ink discharging unit, wherein the ink discharged from the first ink discharging unit A first temperature sensor for outputting temperature information of the second ink ejection unit, and a temperature sensor for outputting temperature information of ink ejected from the second ink ejection unit. A second temperature sensor, a heater of the first ink ejection unit, a first heater for heating ink ejected from the first ink ejection unit, and a second ink ejection unit Providing a second heater for heating the ink ejected from the second ink ejection unit, wherein the temperature information from the first and second temperature sensors is provided. Based on Come, first a control step for performing each of the heating control by the heating control and the second heater by the heater, in the control step, the first
The heating control by the first heater is performed in accordance with the decrease in the ink temperature of the first ink discharging unit accompanying the ink discharging from the ink discharging unit, and the ink is controlled by the ink discharging from the second ink discharging unit. The heating control by the second heater is performed in response to a decrease in the ink temperature of the second ink ejection unit, which is greater than the decrease in the ink temperature of the first ink ejection unit. And

[0007]

According to the above arrangement, the first ink discharge section having the discharge port having a relatively small opening area and the second ink discharge section having the discharge port having a relatively large opening area are formed by:
Each ink temperature is applied to each ink ejection section.
In accordance with the drop in ink temperature due to ink ejection
Is controlled by heating the heater. Therefore, large opening area
In the second ink ejection section, relatively little
Large ink movement occurs and is larger than the first ink ejection section
Causes a significant drop in ink temperature.
It is possible to control the heating of the heater in accordance with
The ink ejection section also controls heating according to the ink temperature drop
Can be performed.

[0008]

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

FIG. 1 is a block diagram showing a configuration of ink temperature control of a recording head in an ink jet recording apparatus according to one embodiment of the present invention.

The above-described ink jet recording apparatus is a known apparatus which performs recording by discharging ink onto a recording medium. In FIG. 1, reference numeral 1 denotes a recording head capable of recording dark and light. The print head 1 includes ejection units 2 and 5 for performing dark and light printing, respectively. The discharge unit 2 detects a plurality of discharge ports 21 having a small discharge port area, a discharge heater 20 provided in correspondence with the discharge ports 21, a warming heater 3 used for heating the temperature of ink discharged from the discharge ports 21, and an ink temperature. It has a sensor 4 to perform. The discharge unit 5 also includes a discharge port 51 having a large discharge port area, a discharge heater 50, a warming heater 6, and a temperature sensor 7.

Numerals 8 and 9 denote circuits for supplying power to the heat retaining heaters 3 and 6 of the discharge sections 2 and 5, respectively.
The power supply by this circuit is controlled based on the temperature information. Further, the microprocessor 10 gives an instruction to the discharge heater control circuit 11 and controls the application of a pulse to each discharge heater based on the discharge information stored in the recording memory 12.

FIG. 2 is a schematic waveform diagram of a pulse applied to each discharge heater. When such a pulse is applied to the ejection heater, the microprocessor 10
The ink temperature of each of the dark and light discharge sections 2 and 5 is individually controlled based on information from the temperature sensors 4 and 7. in this case,
As for the temperature change during printing, in the ejection unit 2 that performs printing with a light density, the amount of ink movement is relatively small, so that the fluctuation range of the ink temperature becomes small, and the heater 3 is repeatedly turned on and off by that amount. As shown in FIG. In contrast,
In the ejection unit 5 that performs printing at a high density, more ink moves, so that the ON time of the heater 6 becomes longer, the amount of overshoot increases, and the ink temperature changes as shown in FIG. become.

As described above, when one recording head is provided with ejection ports having different ejection port areas, an ink temperature control system is provided for each ejection port having a different area. Temperature control can be performed, and recording at a desired density can be performed for each.

Of the two consecutive pulses of the voltage application pulse shown in FIG. 2, the preceding first pulse contributes to heating to such an extent that the ink in the ejection port is not ejected rather than ejecting the ink. I have. For this reason, when the ink temperature is low, the width of the first pulse is increased as shown in FIG. 4A, and when the ink temperature is high, the width of the first pulse is increased as shown in FIG. short and it may be a temperature control combined with heating warmth heater.

As shown in FIG. 5, the microprocessor 10 controls the pulse setting in the discharge heater control units 13 and 14 in accordance with the information from the temperature sensors 7 and 4, respectively, in order of the dark and light discharge units. It can be implemented by performing it individually.

According to each of the above-described embodiments, in addition to the above-described effects, when a large number of print heads are manufactured, variations in the density of the dark print discharge section and the light print discharge section that differ for each print head are reduced. By setting the temperature to be different, the absorption can be achieved.

In a printing mode in which printing is performed by only one of the ejection sections (normally, the first and last lines of one page),
Minimal power required for temperature control.

(Others) The present invention includes a means (for example, an electrothermal converter, a laser beam, or the like) for generating thermal energy as energy used for discharging ink, 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.

The configuration of the recording head may be a combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a 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.

Further, 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, for example, not only those provided for one color ink but also 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 only used as an image output terminal of an information processing apparatus such as a computer, but also for a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. It may take a form.

[0027]

As described above, according to the present invention,
A first ink discharge section having a discharge opening having a relatively small opening area and a discharge opening having a discharge opening having a relatively large opening area;
The second ink ejection unit is adapted to control the temperature of each ink.
Ink associated with ink discharge at each ink discharge unit
It is controlled by heating the heater according to the temperature decrease.
Therefore, in the second ink ejection section having a large opening area,
Ink discharge causes relatively large ink movement and
Causes a larger drop in ink temperature than the ink ejection section
Controls the heating of the heater in response to this drop in ink temperature.
And the first ink ejection unit also
Heating control according to the temperature drop can be performed.

As a result, it is possible to obtain a desired amount of ink to be discharged from each of the discharge ports, and it is possible to perform recording with an appropriate density.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration for controlling the ink temperature of a recording head according to an embodiment of the present invention.

FIG. 2 is a waveform diagram showing a voltage application pulse of the discharge heater shown in FIG.

FIGS. 3A and 3B are diagrams showing changes in the ink temperature of each ejection unit for dark and light printing under the control of the embodiment.

FIGS. 4A and 4B are waveform diagrams showing a voltage application pulse of an ejection heater according to another embodiment of the present invention.

FIG. 5 is a block diagram showing a control configuration of another embodiment shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head 2, 5 Discharge part which performs dark and light recording 3, 6 Insulation heater 4, 7 Temperature sensor 8, 9 Power supply circuit to insulation heater 10 Microprocessor 11, 13, 14 Discharge heater control circuit 20, 50 Discharge Heater 21, 51 Discharge port

Claims (4)

(57) [Claims] 1. A recording apparatus comprising: a first ink ejection section having an ink ejection port having a first opening area; and a second ink ejection section having an ink ejection port having an opening area larger than the first opening area. An ink jet recording apparatus that performs recording by discharging ink from a recording head to a recording medium using a head, a temperature sensor included in the first ink discharging unit,
A first temperature sensor for outputting temperature information of ink ejected from the first ink ejection unit, and a temperature sensor included in the second ink ejection unit,
A second temperature sensor for outputting temperature information of ink ejected from the second ink ejection unit; and a heater included in the first ink ejection unit, wherein the heater is provided in the first ink ejection unit. A first heater for heating the ink to be discharged, and a second heater for heating the ink discharged from the second ink discharge unit, the heater being included in the second ink discharge unit. And control means for performing heating control by the first heater and heating control by the second heater based on temperature information from the first and second temperature sensors, respectively. Performs heating control by the first heater in accordance with a decrease in the ink temperature of the first ink ejection unit due to the ink ejection from the first ink ejection unit, and performs heating control by the second ink ejection unit. Ink ejection Wherein the heating control by the second heater is performed in response to a decrease in the ink temperature of the second ink ejection section caused by the decrease in the ink temperature of the first ink ejection section. Inkjet recording apparatus. 2. The ink jet recording apparatus according to claim 1, wherein the first ink ejection unit and the second ink ejection unit include an ejection heater that generates heat energy used for ejecting ink. apparatus. 3. A recording apparatus comprising: a first ink ejection section having an ink ejection port having a first opening area; and a second ink ejection section having an ink ejection port having an opening area larger than the first opening area. An ink jet recording method for performing recording by ejecting ink from a recording head to a recording medium using a head, comprising: a temperature sensor included in the first ink ejection unit;
A first temperature sensor for outputting temperature information of ink ejected from the first ink ejection section, and a temperature sensor included in the second ink ejection section, wherein A second temperature sensor for outputting temperature information of the ink to be ejected, and a heater included in the first ink ejection unit, the heater being for heating the ink ejected from the first ink ejection unit. A first heater and a heater included in the second ink ejection unit, wherein
Preparing a second heater for heating the ink ejected from the ink ejection unit of the first embodiment; and heating control by the first heater based on temperature information from the first and second temperature sensors. And a control step for performing each of heating control by the second heater. In the control step, the ink temperature of the first ink ejection unit accompanying the ink ejection from the first ink ejection unit is controlled. The heating control by the first heater is performed in accordance with the drop, and the second ink discharging unit is configured to perform the heating control with the ink discharging from the second ink discharging unit.
A drop in the ink temperature of the ink discharge section of
An ink jet recording method, wherein the heating control by the second heater is performed in accordance with a temperature drop larger than a drop in the ink temperature of the ink discharge section. 4. The ink jet recording apparatus according to claim 3, wherein the first ink ejection unit and the second ink ejection unit include an ejection heater that generates heat energy used for ink ejection. Method.