JP2003112428A - Recorder and temperature control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recorder and a temperature control method which reduce power consumption and form images with no density unevenness by reducing irregularities of an ink discharge amount regardless of a bias of used nozzles in an ink jet recording head. SOLUTION: In recording with the use of the full-line ink jet recording head to which a plurality of recording elements including electrothermal conversion bodies are arranged, it is analyzed how much of data for generating an ink discharge per predetermined unit is included in input recording data, and the temperature of the ink jet recording head is detected. Based on the detected result, it is detected whether or not the temperature of the ink jet recording head is within a predetermined range suitable for a recording operation. When the temperature of the ink jet recording head is within the predetermined range by the detection, it is so controlled that a driving signal of a level not to generate the ink discharge is applied to the electrothermal conversion bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus and a temperature control method, and more particularly to a recording apparatus for recording an image on a recording medium using an inkjet recording head and a temperature control method therefor.

[0002]

2. Description of the Related Art Corresponding to image data, a drive signal is applied to an electrothermal converter in a nozzle provided in an ink jet recording head (hereinafter referred to as a recording head) to eject fine ink droplets and In a printing apparatus that prints characters and images on a printing medium such as, printing is not always performed using all nozzles provided in the printing head depending on the image data. For example, you can print by ejecting ink using nozzles on only one half of the recording head,
In some cases, only part of the printhead nozzles are used.

When the nozzles provided in the print head are not used uniformly and there is a bias in the use, the temperature distribution in the print head is also biased, and when printing is performed in this state, the printing is performed. Partial density unevenness occurs in the image. Such uneven temperature distribution in the print head is more likely to occur as the number of nozzles increases. This phenomenon is a serious problem because color balance is lost and a change in tint and a decrease in color reproducibility are caused especially when a color image is recorded using inks such as cyan, magenta, yellow and black. Becomes

In order to solve this problem, the conventional ink jet recording apparatus is driven to such an extent that ink droplets are not ejected even to the electrothermal converters of nozzles (hereinafter also referred to as non-recording nozzles) that do not cause recording By applying a signal (hereinafter also referred to as short pulse driving), the temperature distribution in the print head is prevented from being biased regardless of the bias of the nozzles used in the print head.

By such control, it is possible to reduce the variation in the ink ejection amount and to record an image without density unevenness.

[0006]

However, in the temperature adjusting method by the short pulse drive for reducing the density unevenness according to the above-mentioned conventional example, in order to apply the drive pulse to the electrothermal transducers of all the non-printing nozzles of the printhead. However, there is a problem that the head temperature is likely to be high and the temperature range easily exceeds the optimum temperature range for printing. In particular, even if there is a lot of blank data, that is, even in the case of low duty recording, since the temperature is adjusted by the short pulse drive, the head temperature becomes higher and extra power is consumed for this adjustment. is there.

The present invention has been made in view of the above-described conventional example, and reduces power consumption, reduces variation in ink ejection amount, and suppresses density unevenness regardless of bias of recording elements used in an ink jet recording head. An object of the present invention is to provide a recording apparatus and a temperature control method for forming a non-existent image.

[0008]

In order to achieve the above object, a recording apparatus of the present invention has the following constitution.

That is, a recording apparatus for recording using an ink jet recording head in which a plurality of recording elements including an electrothermal converter having a recording width corresponding to at least the width of a recording medium are arranged, Input means for inputting, an analysis means for checking how much data causing ink ejection per predetermined unit is included in the print data input by the input means, and a detection means for detecting the temperature of the ink jet print head. A determination unit that determines whether the temperature of the inkjet recording head is within a predetermined range suitable for a recording operation based on the detection result of the detection unit; and the temperature of the inkjet recording head is determined by the determination unit. If within the predetermined range, according to the analysis result by the analysis means,
And a control unit that controls to apply a drive signal to the extent that ink is not ejected to the electrothermal converter.

When the temperature of the ink jet recording head is lower than the predetermined range by the discrimination by the discriminating means, the ink is not ejected even on the electrothermal converter of the recording element which does not eject the ink. When the signal is applied and the temperature of the ink jet recording head is higher than a predetermined range, it is controlled to stop the application of the drive signal to the extent that ink is not ejected to the electrothermal converter of the recording element that does not eject ink. Even better.

Further, as a result of the analysis by the analyzing means, the control means applies the drive signal to the extent that ink ejection does not occur when there is no data that causes ink ejection to all of the plurality of recording elements. It may be controlled not to perform, or if there is no data that causes ink ejection to a predetermined number or more of the plurality of recording elements, a drive signal that does not cause ink ejection It may be controlled not to apply.

Further, the analyzing means may divide a plurality of recording elements into a plurality of blocks and check how much data for causing ink ejection is included in each block.

Further, the ink jet recording head is provided with a heater for adjusting temperature separately from the plurality of recording elements, and when the recording operation is not performed, the heater is driven based on the detection result of the detecting means to cause the ink jet recording. It is advisable to adjust the temperature of the recording head uniformly.

It is desirable that the ink jet recording head eject ink by utilizing thermal energy generated by applying a drive signal to the electrothermal converter, and the temperature of the ink jet recording head is about 30 to 40 ° C. Suitable for recording operation.

According to another aspect of the invention, there is provided a recording apparatus for recording by using a recording head in which a plurality of recording elements including electrothermal transducers are arranged, the input means for inputting recording data, and Analysis means for checking how much recording data inputted by the input means includes data for causing recording per predetermined unit for the recording element array of the recording head; and detection means for detecting the temperature of the recording head,
Based on the detection result of the detection unit, a determination unit that determines whether or not the temperature of the recording head is within a predetermined range suitable for the recording operation, and the temperature of the recording head is determined by the determination unit. If within range,
And a control unit that controls to apply a drive signal to the extent that recording on the electrothermal converter does not occur according to the analysis result by the analysis unit.

According to another aspect of the invention, a recording apparatus for recording by using an ink jet recording head in which a plurality of recording elements including an electrothermal converter having a recording width corresponding to at least the width of a recording medium are arranged. The temperature control method of
An input step of inputting print data, an analysis step of checking how much data causing ink ejection per predetermined unit is included in the print data input in the input step, and a detection step of detecting the temperature of the inkjet print head And a determining step of determining whether or not the temperature of the inkjet recording head is within a predetermined range suitable for a recording operation based on the detection result of the detecting step,
When the temperature of the inkjet recording head is within the predetermined range by the determination in the determination step, control is performed according to the analysis result in the analysis step so as to apply the drive signal to the extent that ink is not ejected to the electrothermal converter. And a control step for controlling the temperature.

According to the present invention having the above-described structure, the present invention can be applied to inputting at the time of recording using an ink jet recording head having a recording width corresponding to at least the width of a recording medium and in which a plurality of recording elements including electrothermal transducers are arranged. It analyzes how much data that causes ink ejection per predetermined unit is included in the print data, detects the temperature of the inkjet print head, and based on the detection result, the temperature of the inkjet print head is set to a predetermined value suitable for the printing operation. If the temperature of the inkjet recording head is within a predetermined range by the determination, a drive signal that does not cause ink ejection to the electrothermal converter is applied according to the analysis result. Control.

Further, according to the present invention, at the time of recording using a recording head in which a plurality of recording elements including an electrothermal converter are arranged,
The input print data is analyzed how much data that causes printing per unit is included, the temperature of the print head is detected, and the temperature of the print head is within a predetermined range suitable for printing operation based on the detected result. If the temperature of the recording head is within a predetermined range based on the determination, control is applied according to the analysis result so as to apply a drive signal to the extent that recording on the electrothermal transducer does not occur.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view schematically showing an ink jet recording apparatus which is a typical embodiment of the present invention.

As shown in FIG. 1, the outer periphery of the ink jet recording apparatus 101 is openable and closable in which a feeder tray 102 for accommodating recording media, a full-line recording head (described later) and a recording medium conveying section are housed. Top cover 1
03, an openable / closable front cover 104 accommodating a tank for storing liquid ink to be supplied to a full-line recording head described later, a power switch unit 105, an operation panel 106 for setting an operating environment, recorded It is composed of a stacker 107, etc., on which the recording media of FIG.

FIG. 2 is a side sectional view schematically showing the internal structure of the ink jet recording apparatus.

As shown in FIG. 2, in the transport unit U located below the full line recording head H, the recording medium Pa loaded on the feeder tray 102 is directed to the recording position by the full line recording head H. Is conveyed at a constant speed and reaches its recording position, each of the six heads Bk, C, LC, M and L that compose the full line recording head.
Ink is ejected from M and Y, and an image is recorded on the recording medium. After that, the recording medium Pa on which the image is formed is carried out onto the stacker 107.

Below the transport unit U, each head Bk,
A tank portion R that stores the dedicated ink supplied to C, LC, M, LM, and Y is detachably fixed. The feeder unit F is provided with a recording medium detection width sensor 201 for detecting the width of the loaded recording medium Pa, and when a recording medium having a width different from that of the recording medium on which recording is performed is loaded on the feeder unit F. , Has a function of prompting the user to replace the correct recording medium.

FIG. 3 is a perspective view schematically illustrating the arrangement of the full-line recording head.

The ink jet recording apparatus 101 is equipped with a full line recording head H in which a plurality of recording elements are linearly arranged, and the full line recording head H includes six heads Bk, C, LC, M, LM and Y. It is configured. As shown in FIG. 3, these heads are arranged in parallel with each other in a direction orthogonal to the recording medium conveyance direction. Specifically, a head Bk that ejects black ink to perform recording, a head C that ejects cyan ink to perform recording, and a light cyan ink are ejected in order from the upstream side to the downstream side in the transport direction of the recording medium. A head LC for recording, a head M for ejecting and recording magenta ink, a head LM for ejecting and recording light magenta ink, and a head Y for ejecting and ejecting yellow ink are provided. Furthermore S
H represents a sub-heater, which is provided in each of the head Bk, the head C, the head LC, the head M, the head LM, and the head Y, and is driven so that each head is maintained at a printable temperature.

FIG. 4 is a diagram showing the internal structure of the head of a full line recording head (hereinafter referred to as recording head).

The above-mentioned six heads used in this embodiment have the same structure.

As shown in FIG. 4, the nozzle wall 40
Nozzles 406 that are respectively partitioned by 3 are formed, and the nozzles 406 are provided with electrothermal converters (heaters) 404 corresponding to the respective nozzles. The electrothermal converter 404 is formed on the silicon substrate 401 by a method similar to a semiconductor process, and by applying a predetermined electric energy by a head drive circuit described later,
Bubbles are generated in the ink in the nozzle due to heat, and ink droplets are ejected from the nozzle opening 402.
Reference numeral 405 denotes a common liquid chamber for supplying ink to the nozzles 406, and 407 denotes a top plate.

FIG. 5 is a characteristic diagram showing the relationship between the temperature of the recording head and the optical reflection density (OD value) of the recorded image.

As can be seen from FIG. 5, the density of the recorded image formed on the recording medium changes in proportion to the temperature of the recording head. From this, it is understood that the density unevenness can be suppressed by keeping the print head temperature constant.

In the print head of this embodiment, a temperature sensor (not shown) for detecting the temperature of the print head and a heat-retaining heater (sub-heater S for adjusting the temperature of the print head) are provided.
H) is provided. Then, the temperature of the print head is detected except during the printing operation, and if the temperature is 30 ° C. or less, a current is passed through the sub-heater SH to make the temperature uniform over the entire print head, and the amount of ink droplets ejected from each nozzle. Is made uniform so that an image having no density unevenness is formed.

FIG. 6 is a block diagram showing the control configuration of the host computer 600 and the ink jet recording apparatus 101 of this embodiment.

In FIG. 6, reference numeral 601 denotes a main controller for controlling the entire ink jet recording apparatus, and FIG.
It includes a memory ROM 601a for storing a control program corresponding to the control procedure shown in FIG. 1, a memory RAM 601b used as a work area for executing the control program, and a processing unit CPU 601c for executing the control program. A main controller 601 controls a memory for storing input data from a host computer (hereinafter referred to as a host) 600, a data control for recording,
Also, control is performed according to various setting instructions from the operation panel 106. The main controller 601 is connected to the host 600 via the interface 608 and exchanges signals with each other. Further, the main controller 601 is connected with an image memory 602 which stores data input from the host.

Further, in FIG. 6, reference numeral 603 is a head drive circuit for driving the heating element 404 incorporated in each of the above-mentioned six heads, 604 is a feed motor provided in the recording medium transport section U, and 604D is a feed motor. 60
A recovery motor 60 is provided in a recovery mechanism 512 for performing suction / discharge of the ink with increased viscosity existing in the print head.
Reference numerals 5 and 605D denote motor drivers that drive the recovery system motor 605. The head controller 603, the motor driver 604D, and the motor driver 605D are all controlled by the main controller 601.

An image buffer memory 606 expands the image data transmitted from the host 600 and stores it as bit map data, and temporarily stores the image data recorded by black ink corresponding to the six heads. An image buffer 606Bk, an image buffer 606C that temporarily stores image data recorded with cyan ink, an image buffer 606LC that temporarily stores image data recorded with light cyan ink, and image data recorded with magenta ink. An image buffer 606M for temporarily storing, an image buffer 606LM for temporarily storing image data recorded with light magenta ink, and an image buffer 60 for temporarily storing image data recorded with yellow ink. Consisting of Y. Then, these image buffers are controlled by the driver controller 607.

A drive circuit 609 transmits a drive signal from the main controller to drive the sub heater SH. still,
The sub heater is provided in each head. The temperature of each of the plurality of heads is selectively adjusted by a sub heater. An interface 610 transmits the temperature information of the recording head, and transmits the information of the temperature sensor provided in the recording head to the main controller. The temperature information from the temperature sensor is used for temperature adjustment control of the plurality of recording heads H.

In the above configuration, the image processing is performed based on the image data transmitted from the host 600, the bitmap data corresponding to each ink is stored in each of the six image buffer memories, and the image data for one sheet is stored. When completed, the recording media P loaded on the feeder unit F
The sheets a are sent one after another at a constant speed toward the printing position by the full-line print head H by the number of sheets sent from the host 600. When the conveyed recording medium Pa reaches the recording position, the driver controller 607 connected to the main controller 601 controls the head drive circuit 603 according to the bit map data corresponding to each ink color stored in the image buffer memory 606. Then, an image is formed. Further, the process of receiving the image data from the host 600 and storing the bitmap data in the image buffer memory 606 is performed in parallel with the process of conveying the recording medium and recording the image, so that different images are continuously recorded. It becomes possible to do.

FIG. 7 is a block diagram showing the internal structure of the head drive circuit.

The head drive circuit 603 is in charge of overall drive control of the recording head based on an instruction from the main controller 601. In the inkjet recording apparatus equipped with the recording head H having the above structure, the most suitable head temperature for recording is 30 ° C to 40 ° C.

As shown in FIG. 7, the register setting circuit 90
3 is in the head drive circuit 603, and mainly sets the pulse width of each of the six heads, and transmits the set value to the print control circuit 904. The information on the pulse width is set by the main controller, and is transmitted by activating the WRITE signal and the CS signal and adding the data signal DATA to the address signal ADRS. In addition, control information relating to the temperature information of the recording head is transferred from the main controller 601 to the print control circuit 904. Further, the register setting circuit 903 receives the address signal A
Information related to the print data DATA transmitted together with the DRS, for example, information about the number of nozzles (ink effective print number) in which ink is ejected per line is transmitted to the print data generation circuit 905, and the short pulse control circuit 906 is further provided. The number of short pulse judgment dots is transmitted to.

When the print command generating circuit 905 receives the print command PRINTENB signal from the main controller 601, the print data generating circuit 905 receives the horizontal synchronizing signal HSYNC, that is, the reference clock signal for one line, based on the horizontal synchronizing signal HSYNC. The print data is read from the driver controller 607, and the print data signal ID is supplied to each head.
It outputs ATA and data clock signal DCLK and the like.
Also, every time the pulse of the horizontal synchronizing signal HSYNC rises, the system clock CLK is restored by one clock.
Activates the ART signal, and the short pulse control circuit 906
Reset.

When the PRINTENB signal, which is a print command from the main controller 601, is input to the short pulse control circuit 906, RESTAR is set based on the short pulse determination dot number set by the register setting circuit 903.
When the T signal becomes active, the recording data signal IDAT
A. As a result of counting the ink ejection amount in one line based on the data clock signal DCLK, when it is determined that the number is smaller than the set number of short pulse determination dots, the short pulse drive start signal PHXON is output as active. Therefore, the short pulse control circuit is provided with a register that stores the number of short pulse determination dots, a counter that counts the ink ejection amount in one line, and a comparison circuit that compares the register with the counter. To do.

In the print control circuit 904, when the PRINTENB signal, which is a print command from the main controller 601, is input, the print data signal IDATA and the data clock signal D generated by the print data generation circuit 905.
In accordance with CLK, a time division signal for driving a recording head for printing and a heat pulse signal are output to each recording head, and when the main controller determines that the temperature of the recording head is less than 30 degrees, The judgment information relating to the temperature sent from the main controller is transmitted to the print control circuit 904 via the register setting circuit 903, and the FORCEPHX signal is sent so that the short pulse drive can be performed regardless of the PHXON signal generated by the short pulse control circuit 906. It is validated and output to the short pulse generation circuit 902. And
When the main controller determines that the head temperature is 40 ° C. or lower, the print control circuit 904 generates the PHXENB signal so that the short pulse drive can be performed, and outputs it to the short pulse generation circuit 902. In the short pulse generation circuit 902, when the FORCEPHX signal is valid, or the PHX
When the short pulse drive start signal PHXON is active during the period when the ENB signal is active, the short pulse signal PHX set by the short pulse start signal PHXS and the short pulse end signal PHXE output from the register setting circuit 903 is set to Output to the head.

The short pulse generation circuit 902 receives the signal FORCE.
As described above, the signal PHX for driving the recording head is output by the PHX, the signal PHXENB, the signal PHXON, and the like.

Next, the short pulse control processing of the ink jet recording apparatus having the above construction will be described in detail with reference to the flow chart shown in FIG. In the inkjet recording apparatus equipped with the recording head having the above structure, the most suitable head temperature for recording is 30 ° C to 40 ° C. Note that the control in the head drive circuit shown in FIG. 7 is also described in the flowchart for convenience of description.

Therefore, when the apparatus is in a standby state where recording is not performed, the temperature of the recording head is detected, and when the temperature is lower than the temperature range in which the recording head can optimally eject ink, for example, the head. If the temperature is lower than 30 ° C., in step S100, an electric current is passed through the sub-heater SH to keep the entire recording head H at an optimum temperature.

Thereafter, when data is sent from the host computer 600 to the recording apparatus 101 and the CPU 601C in the main controller determines to start recording, step S
In 110, it is determined whether or not recording on the recording medium is started, and the process proceeds to step S120. If not started, step S10 is performed.
Returning to 0, the sub-heater SH is driven to maintain the optimum head temperature. When recording is started, the main controller causes the register setting circuit to count the number of recording effective dots in one line for each color in step S120, and proceeds to step S130, in which the short pulse control circuit 906 determines the number of recording effective dots and the short pulse. Compare with the number of dots,
The short pulse control circuit 906 outputs the determination result. According to the result, the short pulse control circuit 906 outputs the signal PHXON.
Is output. When the number of recording effective dots is equal to or more than the number of short pulse determination dots set by the register setting circuit 903, the short pulse drive start signal PHXON output from the short pulse control circuit 906 is made valid, and when it is less than that, the short pulse control circuit is made. The short pulse drive activation signal PHXON output from 906 is invalidated.

Next, in step S160, the information of the temperature sensor in the recording head is sent to the processing unit CP via the signal line 610.
If the main controller 601 determines that the temperature inside the head is lower than 30 ° C. which is the lower limit of the optimum ink discharge temperature range, the process proceeds to step S170, and the main controller 601 reads the F
The ORCEPHX signal is controlled to be output, the print control circuit 904 controls the FORCEPHX signal to be valid, and the short pulse generation circuit controls the PHXENB signal and PXENB signal.
Regardless of the input value of the HXON signal, the short pulse drive signal P
With HX enabled, the print head is driven to raise the head temperature and the process proceeds to step S220. If the main controller determines that the temperature in the head is 30 ° C. or more, which is the lower limit of the optimum ink discharge temperature range, the process proceeds to step S180, and the print control circuit is set to F through the register setting circuit.
Control to invalidate the ORCEPHX signal is performed in step S
Proceed to 190. If the main controller determines that the head temperature has exceeded the upper limit of 40 ° C., which is the optimum ink ejection range, the process proceeds to step S200, and the print control circuit is not recorded via the register setting circuit. In order to stop the short pulse drive for the nozzle, PHXEN
Control is performed to invalidate the B signal. To do. This allows
Even if the PHXON signal is valid in step S150, the short pulse drive signal PHX is invalidated, so that the temperature of the entire head does not rise. In this case, a cooling fan or the like may be used to enhance the cooling effect. Then, a process progresses to step S220.

If the main controller determines in step 190 that the temperature inside the head is within 40 ° C. which is the upper limit of the optimum ink ejection range, then PHXEN is sent to the print control circuit via the register setting circuit.
The B signal is controlled to be valid, and step S150 is performed.
If the PHXON signal is valid for the short pulse generation circuit, the short pulse generation circuit 902 controls the short pulse drive signal PHX to perform the short pulse drive.
As a result, the temperature of the head is corrected while suppressing unnecessary temperature rise due to short pulse drive and unnecessary power consumption accompanying this. After that, the process proceeds to S220, executes printing of one line, determines whether the printing is completed in step S230, and repeats step S120 until the printing is completed.
Return to and continue the same process.

This control will be further described with reference to the recording pattern shown in FIG.

FIG. 9 is a diagram showing two recording patterns.

In FIG. 9, the conveyance direction of the recording medium 801 is from the bottom to the top of the paper. In the example of FIG. 9, two patterns 802 and 803 are recorded on the recording medium 801, but the pattern 802 is recorded first, and then the pattern 80.
3 is recorded. When such recording is performed, the specific portion 80 of the recording head is considered from the frequency of use of the recording head.
In 5, a large amount of ink is ejected.

When such recording is continuously performed on a plurality of recording media, if the short pulse drive is not performed at all, a relatively large amount of ink is ejected in the portion 805 of the recording head, so that the head is ejected. The temperature easily rises, and the head temperature does not rise so much in the portion 806 because the frequency of ink ejection is less than that in the portion 805. Therefore, the temperature gradient of the head becomes large near the boundary between the print heads 805 and 806, and as a result, the area 804 in the pattern 803 is formed.
Density unevenness occurs at the right end portion of.

On the other hand, when the short pulse drive is always performed, the nozzles in which ink ejection does not occur are also heated by the short pulse drive while the patterns 802 and 803 are not printed, and as a result, the head is gradually heated. Since the overall temperature rises, the temperature distribution within the recording head has little deviation. As a result, there are no large temperature gradients over the entire recording head, and uneven density can be reduced.

However, if the short pulse drive is always performed, it is inevitable that the entire head becomes high in temperature when low duty recording is continuously performed.

In consideration of this, in this embodiment, the pattern 802 and the pattern 803 are not printed even in continuous printing (that is, there is no print data signal for causing ink ejection in the print data signal for one line). Time)
Since the short pulse drive is not performed, the head temperature rise is reduced as compared with the case where the short pulse drive is always performed. further,
Even if printing is performed, if the number of nozzles that eject ink from the print data signal for one line is less than a predetermined number, the temperature rise accompanying printing is considered to be small, and control is performed not to perform short pulse driving. To do. Such control also reduces the head temperature rise. Even if the above control is performed, since the temperature rise caused by recording is slight, the temperature distribution of the recording head can be suppressed to a state where there is little deviation, and the density unevenness that occurs can be reduced.

Finally, the process proceeds to step S230.
It is checked whether or not a series of printing operations (for example, continuous printing) is completed. If not completed, the process proceeds to step S120, and if completed, the short pulse control process is also completed.

Therefore, according to the embodiment described above, an image without density unevenness is formed regardless of the deviation of the nozzles used in the ink jet recording head, the temperature rise of the head is reduced, and the power consumption accompanying the recording operation is reduced. Can be reduced. Further, as a method of realizing control, it is conceivable to realize the same embodiment by program control or by appropriately allocating program control and control by hardware.

In the above-described embodiment, whether or not the short pulse drive is performed is determined by determining whether or not the number of nozzles that generate ink in one line of the print data signal is less than a predetermined number. However, the present invention is not limited to this. For example, even if the nozzles of the print head are divided into a plurality of blocks, it is checked whether the number of nozzles that eject ink in each block is less than a predetermined number, and short pulse drive control is performed in each block. good.

In the above embodiments, the liquid droplets ejected from the recording head have been described as ink, and the liquid contained in the ink tank has been described as ink. However, the content is limited to ink. It is not something that will be done. For example, to improve the fixability and water resistance of recorded images,
A treatment liquid such as a treatment liquid ejected onto the recording medium in order to improve the image quality may be contained in the ink tank.

In the above-described embodiment, particularly in the ink jet recording system, a means (for example, an electrothermal converter or a laser beam) for generating heat energy as energy used for ejecting ink is provided. High density and high definition recording can be achieved by using a method of causing a change in ink state by energy.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, liquid (ink)
By applying at least one drive signal to the electrothermal transducer arranged corresponding to the sheet or liquid path in which is stored, which corresponds to the recorded information and gives a rapid temperature rise exceeding nucleate boiling. Since the electrothermal converter is caused to generate heat energy to cause film boiling on the heat-acting surface of the recording head, as a result, bubbles in the liquid (ink) corresponding to the drive signal in a one-to-one relationship can be formed. It is valid. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. When the drive signal has a pulse shape, the growth and contraction of the bubbles are immediately and appropriately performed, so that it is possible to achieve the ejection of the liquid (ink) with excellent responsiveness, 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. 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 linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications, The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the heat-acting surface is arranged in a bending region. In addition, for multiple electrothermal converters,
Japanese Unexamined Patent Publication No. 59-123670, which discloses a configuration in which a common slot is used as a discharge portion of the electrothermal converter, and Japanese Patent Laid-Open No. 59-63, which discloses a configuration in which an opening for absorbing a pressure wave of thermal energy is associated with the discharge portion. A configuration based on Japanese Patent No. 138461 may be used.

Further, as a full line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length can be increased by combining a plurality of recording heads as disclosed in the above-mentioned specification. Either of the structure satisfying the requirement or the structure as one recording head integrally formed may be used.

In addition to the cartridge type recording head in which the ink tank is integrally provided in the recording head itself described in the above embodiment, the recording head is mounted on the main body of the apparatus, so that the electrical connection with the main body of the apparatus is improved. A replaceable chip-type recording head that enables various connections and supply of ink from the apparatus main body may be used.

Further, it is preferable to add recovery means for the recording head, preliminary means, etc. to the structure of the recording apparatus described above because the recording operation can be made more stable. Specific examples thereof include capping means for the recording head, cleaning means, pressurizing or sucking means, electrothermal converters or heating elements other than these, or preheating means by a combination thereof. Further, provision of a preliminary ejection mode for performing ejection different from recording is also effective for stable recording.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrally formed or a plurality of combinations may be used. Alternatively, the device may be provided with at least one of full-color mixed colors.

In the above-described embodiments, the explanation is made on the assumption that the ink is a liquid, but even if the ink is solidified at room temperature or lower, it should be softened or liquefied at room temperature. Or, in the inkjet method, it is general that the temperature of the ink itself is adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is in a stable ejection range.
It suffices that the ink is in a liquid state when the use recording signal is applied.

In addition, in order to positively prevent the temperature rise due to thermal energy from being used as energy for changing the state of the ink from the solid state to the liquid state,
Alternatively, in order to prevent the ink from evaporating, an ink that solidifies in a standing state and liquefies by heating may be used. In any case, by applying heat energy, such as ink that is liquefied by applying heat 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 such a case, the ink is retained as a liquid or solid in the recesses or through holes of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. It may be configured to face the electrothermal converter. 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, as a form of the recording apparatus according to the present invention, in addition to one provided integrally or separately as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and further transmission / reception It may take the form of a facsimile machine having a function.

Even when the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), a device including one device (for example, a copying machine or a facsimile device). Etc.)

Further, an object of the present invention is to supply a storage medium (or recording medium) recording a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to supply a computer of the system or apparatus ( Alternatively, by the CPU or MPU) reading and executing the program code stored in the storage medium,
It goes without saying that it will be achieved. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.
Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also based on the instruction of the program code,
An operating system (OS) running on the computer does some or all of the actual processing,
It goes without saying that the processing includes the case where the functions of the above-described embodiments are realized.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion card inserted in the computer or the function expansion unit connected to the computer, based on the instruction of the program code. , The CPU provided in the function expansion card or the function expansion unit performs some or all of the actual processing,
It goes without saying that the processing includes the case where the functions of the above-described embodiments are realized.

In the above example, the program processing is described, but the program processing may be processed by hardware.

[0077]

As described above, according to the present invention, an ink jet recording head in which a plurality of recording elements including an electrothermal converter having a recording width corresponding to at least the width of a recording medium are arranged is used. When recording, analyze how much data that causes ink ejection per predetermined unit is included in the input recording data, detect the temperature of the inkjet recording head, and record the temperature of the inkjet recording head based on the detection result. It is determined whether or not the temperature is within a predetermined range suitable for the operation, and if the temperature of the inkjet recording head is within the predetermined range by the determination, according to the analysis result, ink is not ejected to the electrothermal converter. Since control is performed so that a drive signal is applied, a drive signal that does not cause ink ejection while efficiently reducing power consumption is required efficiently. Applied only to the electrothermal transducer limit the temperature distribution of the recording head can be intended unpolarized, the
There is an effect that it is possible to form a high-quality image having no density unevenness regardless of the uneven use of the recording elements of the recording head, and it is possible to suppress an excessive temperature rise of the recording head.

As described above, according to the present invention, when recording is performed using a recording head in which a plurality of recording elements including electrothermal transducers are arranged, data that causes recording per predetermined unit in input recording data. Is detected, the temperature of the recording head is detected, and based on the detection result, it is determined whether the temperature of the recording head is within a predetermined range suitable for recording operation. When the temperature of the recording head is within a predetermined range, according to the analysis result, the driving signal is controlled to be applied to the electrothermal transducer so that the recording is not generated, so that the recording is not generated while the power consumption is suppressed. Drive signal can be efficiently applied to the electrothermal converter to the minimum necessary to make the temperature distribution of the recording head non-uniform. Can form a high quality image without density unevenness, also there is an effect that it is possible to suppress the temperature increase of the excessive recording head.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an inkjet recording apparatus that is a typical embodiment of the present invention.

FIG. 2 is a side sectional view schematically showing the internal configuration of the inkjet recording apparatus.

FIG. 3 is a perspective view schematically illustrating an arrangement of full line recording heads.

FIG. 4 is an internal structural diagram of a full line recording head.

FIG. 5 is a characteristic diagram showing the relationship between the temperature of the recording head and the optical reflection density (OD value) of a recorded image.

FIG. 6 is a block diagram showing a control configuration of the inkjet recording apparatus.

FIG. 7 is a block diagram showing an internal configuration of a head drive circuit.

FIG. 8 is a flowchart showing a short pulse control process.

FIG. 9 is a diagram showing two recording patterns.

[Explanation of symbols]

101 inkjet recording apparatus 102 feeder tray 103 top cover 104 front cover 105 power switch 106 Operation panel 107 Stacker tray F feeder unit U transport unit R tank section Pa recording medium H full line recording head Bk Black ink head C Cyan ink head LC Light cyan ink head Head for magenta ink LM Light magenta ink head Y Yellow ink head 600 host computer 601 Main controller 602 image memory 603 head drive circuit 604 Feed motor 604D motor driver 605 Recovery motor 605D motor driver 606 image buffer memory 609 Recording medium width detection sensor

Claims (13)

[Claims] 1. A recording apparatus for performing recording using an inkjet recording head having a recording width corresponding to at least the width of a recording medium and in which a plurality of recording elements including electrothermal transducers are arranged, wherein: Input means for inputting, an analysis means for checking how much data for causing ink ejection per predetermined unit is included in the print data input by the input means, and a detection means for detecting the temperature of the inkjet print head A determination unit that determines whether the temperature of the inkjet recording head is within a predetermined range suitable for a recording operation based on the detection result of the detection unit; and the temperature of the inkjet recording head is determined by the determination unit. If within the predetermined range, according to the analysis result by the analysis means, for the electrothermal converter Recording apparatus characterized by a control means for controlling to perform the application of the extent of the drive signal link discharge does not occur. 2. When the temperature of the ink jet recording head is lower than the predetermined range by the determination by the determining means, a heating means for heating the electrothermal converter of the recording element that does not eject ink is further provided. The recording apparatus according to claim 1, wherein: 3. When the temperature of the ink jet recording head is higher than the predetermined range by the discrimination by the discriminating means, a drive signal that does not cause ink ejection to the electrothermal converter of the recording element that does not eject the ink. The recording apparatus according to claim 2, further comprising a heating stop unit that stops the application of the heat. 4. The control unit applies a drive signal to the extent that ink ejection does not occur if there is no data that causes ink ejection to all of the plurality of recording elements as a result of analysis by the analysis unit. The recording apparatus according to claim 1, wherein the recording apparatus is controlled so as not to perform. 5. The control unit ejects ink when there is no data that causes ink ejection to a predetermined number or more of the plurality of recording elements as a result of the analysis by the analyzing unit. The recording apparatus according to claim 1, wherein the recording apparatus is controlled so that the drive signal is not applied to the extent that the occurrence of the above problem does not occur. 6. The analysis unit divides the plurality of recording elements into a plurality of blocks, and checks how much data is included in each block to cause ink ejection. The recording device described. 7. The ink jet recording head is provided with a heater for adjusting temperature separately from the plurality of recording elements, and when the recording operation is not performed, the heater is driven based on the detection result of the detection means. The recording apparatus according to claim 1, further comprising adjusting means for uniformly adjusting the temperature of the inkjet recording head. 8. The recording apparatus according to claim 1, wherein the inkjet recording head ejects ink by using thermal energy generated by applying a drive signal to the electrothermal converter. 9. The recording apparatus according to claim 1, wherein the temperature range of the ink jet recording head suitable for recording operation is about 30 to 40 ° C. 10. A temperature control method for a recording apparatus, wherein recording is performed using an inkjet recording head in which a plurality of recording elements including an electrothermal converter having a recording width corresponding to at least the width of a recording medium are arranged. An input step of inputting print data, an analysis step of checking how much data causing ink ejection per predetermined unit is included in the print data input in the input step, and a temperature of the inkjet print head is detected. And a determination step of determining whether or not the temperature of the inkjet recording head is within a predetermined range suitable for a recording operation based on the detection result of the detection step, and the inkjet recording by the determination step. If the temperature of the head is within the predetermined range, according to the analysis result in the analysis step, Temperature control method characterized by a control step of controlling to perform application of the drive signals to the extent that the ink ejection for the heat converters is not caused. 11. A recording apparatus for recording by using a recording head in which a plurality of recording elements including electrothermal transducers are arranged, the input device inputting recording data, and the input device. Based on the detection result by the detection unit, an analysis unit that checks how much data that causes recording for a predetermined unit in the recording element array of the recording head is included in the recording data, a detection unit that detects the temperature of the recording head, Determining means for determining whether or not the temperature of the recording head is within a predetermined range suitable for a recording operation, and if the temperature of the recording head is within the predetermined range by the determination by the determining means, the analysis is performed. And a control means for controlling so as to apply a drive signal to such an extent that recording does not occur on the electrothermal converter according to the analysis result by the means. Recording device for the butterflies. 12. The heating means for heating the inkjet recording head when the temperature of the inkjet recording head is lower than the predetermined range according to the determination by the determining means. Recording device. 13. Control means for controlling to apply a drive signal to the extent that recording does not occur on the ink jet recording head when the temperature of the ink jet recording head is higher than the predetermined range by the discrimination by the discrimination means. The recording apparatus according to claim 11, further comprising means for stopping the operation of.