JPH08323983A - Method for recording and device therefor - Google Patents

Abstract

PURPOSE: To maintain the high quality of printing and to lower power by allowing a memory means the thermal insulation drive control of a heating means in recording recording information of memory when an effective picture element percentage measured by a measuring means is not exceeding a prescribed value. CONSTITUTION: Before printing the respective contents of a print buffer 101, the contents of the number of effective dots in the buffer are counted (102). Next, the average density (effective picture element percentage) of an image is obtained from the counted value, and a printing mode is determined from the average density (104). For example, when the respective effective picture element percentages of the print buffer are smaller or either of them is greater than a prescribed value, the recording is conducted simultaneously or independently. Next, the effective picture percentage is checked whether it is larger than a prescribed value C or not (105). When it is larger, the temperature control of a head is prohibited (106), and printing process is conducted (108). When it is not larger, the temperature control of the head is permitted (107), and the additional increase in total power by power supply to a heater is prevented during a high duty time of large power consumption.

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 method for performing recording by sequentially scanning a recording head having a plurality of recording elements in a direction perpendicular to a recording paper conveyance direction.

[0002]

2. Description of the Related Art Conventionally, there are a thermal transfer system, an inkjet system, etc. in a serial printer. Each of these devices has a plurality of recording element arrays, the recording element arrays are arranged in parallel with the recording paper conveyance direction, and the recording element arrays are sequentially scanned in the direction perpendicular to the paper conveyance direction.
Achieve a printout of one sheet of recording paper.

By the way, in recent years, there is a remarkable tendency to increase the number of recording elements included in the recording element array (longer recording head) in order to achieve higher printing speed. However, problems associated with such lengthening include an increase in the capacity of the power supply, an increase in the size of the power supply, and an increase in cost.

Recently, due to the advancement of switching power supply technology, small-sized, high-efficiency, high-power switching adapters have become popular, but such adapters are more expensive than conventional transformer type AC adapters.

The increase in the power required for the power supply as described above is due to the increase in the power required for recording accompanying the lengthening of the recording head. That is, as the number of printing elements increases, the number of printing elements that must be driven within a unit time also increases. For example, an image having an average Z [%] density is recorded by an inkjet recording head having n nozzles.
The power Pn when recording with the ejection frequency f [Hz] and the drive pulse width T [sec] is

[0006]

[Equation 1]

Pn = (I · V · n) · (T · f) · Z Equation (1) is obtained. Here, I is the peak value of the rectangular pulse current flowing through each recording element, and V is the power supply voltage value.

[0008]

As can be seen from the equation (1), the power Pn increases as the number of nozzles n increases, the ejection frequency f increases, and the average density further increases. Therefore, it is necessary to reduce these in order to achieve a high number of nozzles for high-speed printing and reduce the power. However, Z is unique to the image, and a decrease in f causes a decrease in printing speed. , Not suitable.

Further, some recording heads have a heat-retaining heater in order to improve the quality of printing. For example, by controlling the temperature of the head to a constant value, it is possible to control the ink ejection amount to a constant value. carry out. Especially in a low-temperature environment Next, there is a case where the heaters for heat retention are driven and controlled in parallel during printing. When the heaters have to be turned on, in addition to the original heating of the element for ink ejection, the heater Heating is superposed and a large amount of electric power is required.

It is an object of the present invention to provide a recording apparatus and method for maintaining high printing quality of a recording element using a long recording head for high speed printing and achieving low power.

[0011]

In order to achieve the above object, the present invention is provided with the following configuration, for example.

That is, in a recording apparatus for performing recording by sequentially scanning a recording head having a plurality of recording elements in a direction perpendicular to the recording paper conveyance direction, heater means for keeping the recording head warm and recording information for at least one line. Storing means capable of storing the effective pixel ratio of the record information stored in the storing means, and storing in the storing means when the effective pixel ratio measured by the measuring means is equal to or less than a predetermined value. The heater control means for permitting the heat retention drive control of the heater means during the recording of the record information.

Further, for example, the measuring means measures the effective pixel ratio of the recording information for one line of the storage means. Alternatively, the measuring means is characterized in that the storage means is divided into a plurality of sections, and the effective pixel ratio in each of the plurality of divided sections is measured, for example, the heater control means is in each section measured by the measuring means. When all the effective pixel ratios are equal to or less than a predetermined value, the warming drive control of the heater means during the recording of the record information stored in the storage means is permitted.

With the above construction, in order to measure the effective pixel ratio of recorded information before recording, printing of low density such as text data and high density of graphics data or image in one recording are performed. Even when printing of data and the like is mixed, it is possible to perform optimum heat retention drive control corresponding to each printing. Therefore, it is possible to effectively prevent an unnecessary increase in power consumption when the recording head is driven, and it is possible to provide a recording apparatus and method that maintain high printing quality and achieve low power consumption.

Furthermore, by measuring the effective pixel ratio for each line, effective power consumption reduction can be achieved with simple control.

Furthermore, by dividing the storage means into a plurality of sections and measuring the effective pixel ratio in each of the plurality of sections thus divided, it is possible to achieve finer power consumption reduction.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described in detail below with reference to the drawings.

[First Embodiment] <General Description of Apparatus Main Body> FIG. 1 is an external perspective view showing the outline of the configuration of an ink jet printer IJRA which is a typical embodiment of the present invention. In FIG. 1, the drive motor 5
The driving force transmission gear 5011 is interlocked with the forward / reverse rotation of 013,
The carriage HC that engages with the spiral groove 5004 of the lead screw 5005 that rotates via 5009 has a pin (not shown) and is reciprocated in the directions of arrows a and b.
An inkjet cartridge IJC is mounted on the carriage HC. 5002 is a paper pressing plate,
The paper is pressed against the platen 5000 in the moving direction of the carriage. Reference numerals 5007 and 5008 denote photocouplers, which are home position detecting means for confirming the presence of the carriage lever 5006 in this area and switching the rotation direction of the motor 5013. Reference numeral 5016 is a member that supports a cap member 5022 that caps the front surface of the recording head. Reference numeral 5015 is a suction unit that sucks the inside of the cap, and performs suction recovery of the recording head through the in-cap opening 5023. Reference numeral 5017 is a cleaning blade, and 5019 is a member that allows this blade to move in the front-rear direction, and these are supported by a main body support plate 5018. Needless to say, a well-known cleaning blade can be applied to this example instead of this form.
Reference numeral 5012 denotes a lever for starting suction for suction recovery, which moves in accordance with the movement of the cam 5020 that engages with the carriage, and the movement of the driving force from the driving motor is controlled by a known transmission means such as clutch switching. To be done.

The capping, cleaning, and suction recovery are configured so that the desired processing can be performed at their corresponding positions by the action of the lead screw 5005 when the carriage comes to the area on the home position side. As long as the desired operation is performed at the timing, any of the above can be applied to this example.

<Description of Control Configuration> Next, a control configuration for executing the recording control of the above-mentioned apparatus will be described.
FIG. 2 is a block diagram showing the configuration of the control circuit of the inkjet printer IJRA. In the figure showing a control circuit, 1700 is an interface for inputting a recording signal, 1
Reference numeral 701 denotes an MPU, 1702 denotes a program ROM that stores a control program executed by the MPU 1701, and 1703.
Is a dynamic RAM for storing various data (recording data, recording data supplied to the head, etc.). A gate array 1704 controls supply of print data to the print head 1708, and also controls data transfer between the interface 1700, the MPU 1701, and the RAM 1703. Reference numeral 1710 is a carrier motor for carrying the recording head 1708, and 1709 is a carrying motor for carrying the recording paper. Reference numeral 1705 is a head driver for driving the head, and 1706 and 1707 are motor drivers for driving the carry motor 1709 and the carrier motor 1710, respectively.

The operation of the above control structure will be described. When a recording signal is input to the interface 1700, the gate array 17
The print signal is converted between the print signal 04 and the MPU 1701 to print data for printing. Then, the motor driver 17
06 and 1707 are driven, and the head driver 1
The print head is driven according to the print data sent to 705, and printing is performed.

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, and the thermal energy The printing apparatus of the type that causes a change in the state of ink has been described. According to such a method, the recording density is increased,
High definition can be achieved.

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4740.
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 converter arranged corresponding to the sheet or liquid path in which the liquid crystal is held, which corresponds to the recorded information and causes a rapid temperature rise exceeding film 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. It is more preferable to make this drive signal in a pulse shape, because bubbles can be grown and contracted immediately and appropriately, and thus a 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 ejection 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, 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 structure in which a common slot is used as a discharge portion of an electrothermal converter, and Japanese Patent Laid-Open No. 59-63, which discloses a structure 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 which 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, by being attached to the apparatus main body, it can be electrically connected to the apparatus main body and can be supplied with ink from the apparatus main body by a replaceable chip type recording head or the recording head itself. Alternatively, a cartridge type recording head provided with an ink tank may be used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a constitution of the recording apparatus of the present invention, because the effect of the present invention can be further stabilized. . Specific examples thereof include capping means, cleaning means, pressurizing or suctioning means for the recording head, preheating means using an electrothermal converter or another heating element or a combination thereof, and recording. It is also effective to perform a stable recording by performing a preliminary discharge mode in which another discharge is performed. In the present embodiment, the control in the case where the preheating means by the heating element or the combination thereof is provided will be described. The details will be described later.

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 embodiments of the present invention described above, the ink is described as a liquid, but an ink that solidifies at room temperature or lower, or one that softens or liquefies at room temperature may be used, or In the inkjet method, it is common to control the temperature of the ink itself within a range of 30 ° C to 70 ° C to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. It is sufficient that the ink is liquid.

In addition, in order to positively prevent the temperature rise due to thermal energy from being used as the 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.

Next, a characteristic structure of this embodiment having the above basic structure will be described. In this embodiment, as described above, the recording head is provided with a heating element (heater) or a preheating means by a combination thereof, and the recording head is provided with 360 as shown in FIG.
An inkjet recording head with 128 nozzles of dpi (dot per inch) is used.

The recording head has 128 nozzles as described above, but due to the nature of a general serial printer, data is transferred from the host computer based on the data of one line of text. Therefore, it is necessary to provide a print buffer for at least this one line. In this embodiment, this print buffer is formed in the DRAM 1703 of FIG. FIG. 4 shows the D shown in FIG. 2 in this embodiment.
FIG. 6 is a diagram showing a configuration of a print buffer in a RAM 1703. As shown in FIG. 4, it is based on a band structure having a width of 64 dots.

For example, in the case of an X24E system emulation mode recording device, a printer having a resolution of 360 dpi typically has a typical size corresponding to A4 size recording paper in the print buffer as shown in FIG. A character having a width of 36 dots and a height of 60 dots is stored in a maximum of 80 digits per line. That is, the number of effective dots in the horizontal direction is 2880 dots (36 × 80) (see FIG. 4).

When actually printing the contents of this print buffer, as shown on the right side of FIG.
It is necessary to print the area between the lines of the buffer (hatched portion), that is, 4 dots. The conversion from the data in the print buffer on the left side to the actual print result on the right side is achieved by dedicated hardware or software. Since such a part is a technique that is not directly related to the present invention, detailed description thereof will be omitted here.

As shown in FIG. 4, each print buffer has a width of 64 dots, and the 64 dots are divided into units of 8 dots. That is, 8 dots correspond to 1 byte of data. The numbers in the figure indicate the lower 8 bits of the byte address, and the address advances to the right of the buffer.
One print buffer is 23040 bytes (8 x 2
880 bytes). The same applies to the print buffers 2, 3, and 4.

In this embodiment, four print buffers are used, the contents of buffers 1 and 2 are printed at the same time, and the contents of buffers 3 and 4 are printed at the same time. Since there are four buffers, the contents to be printed next are stored in the buffers 3 and 4 while the contents of the buffers 1 and 2 are being printed. Similarly, the contents to be printed next can be stored in the buffers 1 and 2 while the contents of the buffers 3 and 4 are being printed, and the contents can be printed out continuously without interruption.

In the recording apparatus of this embodiment, 128 shown in FIG.
A nozzle recording head is used, and this head is used, for example, with a power supply voltage of 24 V, a pulse current of 200 mA, a frequency of 6.25K
It drives with Hz and a drive pulse width of 5 us. At this time, when solid black printing is performed, the power consumption in the head is as described in (1) above.
From the formula, it will be approximately 23 watts (W). Assuming that the efficiency η of the DC-DC converter or the switching power supply for generating the head voltage with higher accuracy is 80%, for example, the power consumed when actually seen from the input of the power supply is about 29 watts.

Further, in this embodiment, in order to improve the printing quality, the temperature control of the head described below is carried out. Figure 6
7 and 8 show an example of the structure of the heater board in the recording head. The heater board is based on a silicon substrate.

Reference numeral 43 in FIG. 6 denotes 128 heating elements, 42 denotes a temperature sensor utilizing a meandering pattern of aluminum, 4
Reference numeral 5 is a wire bonding pad, and 48 is a heat retention heater. FIG. 7 is an enlarged view of the upper right portion of FIG. The temperature sensor 42 uses the aluminum resistance temperature coefficient to detect the temperature of the heater board. Specifically, as the temperature rises, the resistance value of aluminum increases at a constant rate, so this characteristic is used to detect the temperature of the heater board. Then, during printing, this is a constant temperature (eg 40
Control so that it is maintained at (° C). This is generally due to the need to correct the tendency for the ink ejection amount to increase as the heater board temperature rises, and the ink ejection amount is always kept constant by controlling the heater board temperature to a constant value. . This maintains high-quality printing without density fluctuation.

Further, the inkjet used in this embodiment
In printers, etc., in addition to this, a power supply for logic (usually 5
V), a power source for the paper feed motor and a motor for driving the recording head / carriage (may be shared with the power source for driving the head), and the like, the total power required for the power source is 35 It will be ~ 40W. Providing such electric power with an inexpensive AC adapter or the like is not practical because the shape and weight of the AC adapter increase in size and weight. Therefore, in order to realize such a power supply, a switching type adapter is usually used. However, although such an adapter achieves miniaturization, it is expensive in cost. Focusing on this point, in the present embodiment, the power consumption is reduced by adopting the following control method.

FIG. 8 shows the temperature control of the heater board of this embodiment. This temperature control is performed by the ROM 1702 in FIG.
The MPU 1701 controls the gate array 1604 and others in accordance with the control procedure stored in. In order to solve the above-mentioned problem, in this embodiment, before printing the contents of each print buffer (block 101 in FIG. 8) shown in FIG. 4, the number of effective dots in the buffer shown in block 102,
That is, the number of recorded black dots is counted. This is counted by transferring the data in the buffer to a dot count circuit (not shown) using DMA control.

Next, in block 103, the average density of the image recorded by the buffer, in other words, the effective pixel rate is calculated from the count value. This is obtained by calculating the ratio of pixels that are actually recorded and output in all recordable pixels. Then, in block 104, the print mode (recording mode) is determined based on the effective pixel ratio thus obtained. For example, when the effective pixel ratios of both print buffers 1 and 2 are smaller than a predetermined value, the contents of print buffers 1 and 2 are recorded at the same time, but either of print buffers 1 or 2 is effective. When the pixel ratio is larger than the predetermined value, the contents of each print buffer are printed independently. That is, print the first scan
The contents of the buffer 1 are recorded, and the contents of the print buffer 2 are recorded in the second scan.

Alternatively, as shown in FIG. 9, the contents of the print buffers 1 and 2 may be recorded in two staggered scans. In FIG. 9, for example, dots corresponding to black locations are printed in the first scan, and dots corresponding to white locations are printed in the second scan.
The print buffers 3 and 4 are similarly controlled.

Next, in block 105, it is checked whether the effective pixel rate is larger than a predetermined value C or not. When the effective pixel ratio is larger than the predetermined value C, the process proceeds to block 106, and the temperature control of the head by the heater (48 in FIGS. 6 and 7) is prohibited. That is, the power supply to the heater is cut off. Then, the process shifts to the printing process of block 108.

On the other hand, when the effective pixel ratio is not larger than the predetermined value C in the judgment of block 105, the process moves to block 107 to permit the temperature control of the recording head. As a result, it is possible to prevent an increase in total electric power due to the electric power supply to the heater at the time of high duty that consumes a large amount of electric power, and it is possible to use the low capacity power source.

In fact, in high-duty printing, the temperature is kept high even when the heat-retaining heater is off, so that even in a low temperature environment, no particular deterioration in image quality due to a decrease in density is observed. On the other hand, in low-duty printing of text or the like, temperature control is permitted, and a decrease in density can be avoided.

Finally, in block 108, block 104
Printing is actually executed in accordance with the print mode determined in.

By performing the temperature control of the recording head described above, in an image having a high effective pixel ratio such as a graphics or an image image, substantially half of the long recording head corresponding to one scanning, that is, Since the recording progresses while using 64 nozzles, the average power consumption in the recording head is halved. On the other hand, in normal printing such as text printing with a low effective pixel rate, printing is advanced using all 128 nozzles, and high-speed printing is realized.

Further, in this embodiment, in order to measure the effective pixel rate before recording the contents of the print buffer,
Even when low-density text printing and high-density graphics or image printing coexist in one recording, 128 nozzles are used and 64 are used corresponding to each printing.
The use of nozzles can be applied flexibly.

[Second Embodiment] A second embodiment according to the present invention will be described below. In the above first embodiment,
Although the temperature control process shown in FIG. 8 is executed, the present invention is not limited to the above example. In the second embodiment, the temperature adjustment processing and recording control shown in FIG. 10 are executed instead of the processing shown in FIG. 8 of the first embodiment described above.

Also in the second embodiment, the basic structure and the basic control are the same as those in the above-mentioned first embodiment. In the second embodiment, in the processing shown in FIG. 8 of the first embodiment, the processing from block 101 to the determination of the print mode shown in block 104 is the same, but the subsequent processing is different. The different processing will be described below with reference to FIG.

In the second embodiment, if the result of the print mode determination in block 104 shown in FIG. 8 is a plurality of passes, the temperature adjustment process of FIG. 10 is performed. That is, first, block 20
At 1, it is checked whether the next print is the print output from the print buffers 1 and 2 or the print output from the print buffers 3 and 4. In the case of print output from the print buffers 1 and 2, the process proceeds to block 202, first, the effective dots of the print buffer 1 are counted, and the effective print ratio S1 is calculated.
Is calculated. Subsequently, in block 203, the effective dots of the print buffer 2 are counted, and the effective printing rate S2 is calculated. Then, the process proceeds to block 210.

On the other hand, if the print output from the print buffers 3 and 4 in block 201, block 20
The process shifts to the process of No. 4, and the effective dots of the print buffer 3 are counted, and the effective printing rate S3 is calculated. Subsequently, in block 205, the effective dots in the print buffer 4 are counted,
The effective printing rate S4 is calculated. Then, the process proceeds to block 210.

In block 210, it is checked whether or not S1 and S2 (or S3 and S4) calculated in the above processing are lower limit threshold values, for example, 30% or less. Here, when S1 and S2 (or S3 and S4) are less than or equal to the lower limit threshold value (in the case of normal recording with a low effective pixel ratio such as text printing), the process proceeds to block 211 and the heater (FIG. 6, FIG. Figure 7
48) of the head is prohibited. That is, the power supply to the heater is cut off. Then, in the printing process of block 212, recording is advanced using all 128 nozzles of the recording head, and high-speed printing is realized.

On the other hand, in block 210, if S1 and S2 (or S3 and S4) are not less than or equal to the lower threshold value, the process proceeds to block 215, where S1 and S2 (or S3 and S4) is the upper threshold value, For example, compare with 80%. Here, if S1 and S2 (or S3 and S4) are greater than or equal to the upper threshold value (in the case of image recording with a high effective pixel ratio such as graphics or image images), block 2
The process proceeds to 16 and the temperature control of the head by the heater (48 in FIGS. 6 and 7) is prohibited. That is, the power supply to the heater is cut off. Then, in the printing process of the block 218, substantially half the length of the long print head, that is, 6 is obtained, corresponding to one scan.
Recording progresses using four nozzles, and recording is performed in line units by a total of two recordings.

On the other hand, in the determination of block 215, S1 and S
When 2 (or S3 and S4) is not larger than the upper limit threshold value, the process proceeds to block 217, and the temperature control of the recording head is permitted. As a result, it is possible to prevent an increase in total electric power due to the electric power supply to the heater at the time of high duty that consumes a large amount of electric power, and it is possible to use the low capacity power source. Then, the processing of block 218 described above is performed.

As described above, according to the second embodiment, by using the above-mentioned recording method, it is possible to reduce the number of images in the image having a high effective pixel rate such as graphics or image by one.
Corresponding to a single scan, substantially half of the long print head,
That is, since the recording progresses while using 64 nozzles, the average power consumption of the recording head is halved. on the other hand,
1 for normal recording with low effective pixel rate such as text printing
Recording is advanced using all 28 nozzles, and high-speed printing is realized.

Further, as in the first embodiment described above, in order to measure the effective pixel ratio before recording the contents of the print buffer, low density text printing and high density printing are performed in one recording. Even when density graphics or image printing are mixed, the use of 128 nozzles and the use of 64 nozzles can be flexibly applied corresponding to each printing.

[Third Embodiment] Further, in the above description, an example in which the temperature control control is changed by the print rate for each line buffer has been described, but the present invention is not limited to the above example. Further, one print buffer is further divided into a plurality of sections, effective print dots in each of the divided sections (areas) are counted, and temperature control and recording control are executed according to the result.

Also in the third embodiment, the basic configuration and the basic control are the same as in the second embodiment, and the printing modes shown in blocks 101 to 104 in the process shown in FIG. The process up to the determination is similar to that of the first embodiment, but the subsequent process is different. The different processing will be described below with reference to FIG.

In the third embodiment, one print buffer shown in FIG. 4 is divided into 16 sections. For example,
The effective print area of 2880 dot width is divided into 16 areas, and one area is defined as 180 dots. FIG. 12 is a diagram showing an example of division of the print buffer in the third embodiment according to the present invention.

Then, a density flag register for storing the result of indexing the effective pixel ratio of each section divided into 16 of each drawing area of FIG. 12 with 0 or 1 is defined. An example of this density flag register is shown in FIG. The density flag register indexes, for example, "1" when the effective pixel rate is 35% or more and "0" when the effective pixel rate is less than 35%.
Bit 15 of the density flag register corresponds to section 1, bit 14 corresponds to section 2, and so on, bit 0 corresponds to section 16.

In the third embodiment, if the result of the print mode determination in block 104 shown in FIG. 8 is a plurality of passes, the process proceeds to the temperature adjustment process in FIG. Is the print output from the print buffers 1 and 2 or the print output from the print buffers 3 and 4. In the case of print output from the print buffers 1 and 2, the process proceeds to block 302, first, the effective dots of each section are counted for each of the 16 sections of the print buffer 1, and the corresponding section in the density flag register described above is counted. The density flag of is determined.

Subsequently, in block 303, the effective dots in each section are counted for each of the 16 sections of the print buffer 2, and the density flag of the corresponding section in the density flag register is determined. . Then, the process proceeds to block 310.

On the other hand, if the print output is from the print buffers 3 and 4 in block 301, block 30
In step 4, the effective dots in each section are counted for each of the 16 sections of the print buffer 3, and the density flag of the corresponding section in the above-described density flag register is determined. Then at block 305, print buffer 4
The effective dots of each section are counted for each of the 16 divided sections, and the density flag of the corresponding section in the above-described density flag register is determined. Then, the process proceeds to block 310.

In the example shown in FIG. 12, four drawing areas 1-4 are shown, and each of the drawing areas 1-4 corresponds to the print buffer 1-4 shown in FIG. Corresponding to each section of the drawing areas 1 and 2, a plurality of types of printing states are shown, and the% display shown there is included in the effective pixel ratio in that section, that is, in each section obtained by the above processing. The ratio of the number of dots actually printed to the total number of dots displayed is shown.

For example, the section 2 of the drawing area 2 is shown in solid black printing, and the effective pixel rate is 100%. In addition, solid black printing occupies a part of the sections 4 and 5 of the drawing areas 1 and 2, and the ratio (3 in the figure
5% or more) corresponds to the effective pixel rate. Further, the effective pixel ratio 5 is 5 for both the partitions 6 of the drawing areas 1 and 2.
Shown with 0% halftone. The areas 13 and 13 in the drawing areas 1 and 2 are shown such that the ratio of solid black print areas is 35% or less of the area of one area.

FIG. 14 shows the contents of the density flag registers corresponding to the drawing areas 1 and 2 shown in FIG. 12 as an example. As shown in FIG. 14, since the effective pixel ratios of the partitions 1 to 3 of the drawing area 1 are 0%, the bits 15 to 13 are
Is 0. Since the partitions 4 and 5 are each shown with an effective pixel rate of 35% or more, the bits 12 and 11 are 1. Similarly, up to bit 0 is associated. Similarly to the case of the drawing area 1, the contents of the density flag register are associated with the drawing area 2 as shown in FIG. Although the drawing areas 3 and 4 are not shown, this is also processed in the same manner as the case of the drawing areas 1 and 2.

Next, using the density flag register defined as described above at block 310, the drawing area 1
The result of the density flag register corresponding to (or 3),
The logical sum of the results of the density flag register corresponding to the drawing area 2 (or 4) is calculated. The results are shown in the lower part of FIG. Then, it is checked whether this logical sum is "0".
When this logical sum is "0" (in the case of normal printing with a low effective pixel rate such as text printing), the process proceeds to block 311, and head temperature control by the heater (48 in FIGS. 6 and 7) is performed. Ban. That is, the power supply to the heater is cut off. Then, in the printing process of block 312, one of the recording heads
Recording is advanced using all 28 nozzles, and high-speed printing is realized.

On the other hand, in block 310, this logical sum is "
If it is not 0 ", the process shifts to the processing of block 315.
For example, the logical sum result corresponding to the example of FIG. 12 is not 0. That is, this is in either drawing area 1 or 2.
This means that there is a section whose effective pixel rate is 35% or more. In the third embodiment, in such a case, the drawing areas 1 and 2 are printed by two operations.

That is, in block 315, it is checked whether or not there is a partition in which the effective pixel ratio is the upper limit threshold value, for example, 80% or more. Here, when there is a section where the effective pixel rate is equal to or higher than the upper threshold value (when there is an image recording section with a high effective pixel rate such as graphics or image)
Then, the process proceeds to block 316, and the heater (4 in FIG. 6 and FIG. 7) is
The temperature control of the head by 8) is prohibited. That is, the power supply to the heater is cut off. Then, in the printing process of the block 318, in response to one scanning, the printing progresses using substantially half of the long print head, that is, 64 nozzles,
Recording is performed on a line-by-line basis for a total of two recordings.

That is, in the third embodiment, when the logical sum is not 0 (when there is at least one segment whose duty exceeds 80%), the temperature control during printing of this line is prohibited. This prevents the power supply from dropping due to the heat insulation heater being turned on.

On the other hand, if it is determined in block 315 that the effective pixel ratio is not larger than the upper limit threshold value, block 31
7, the temperature control of the recording head is permitted. As a result, it is possible to prevent an increase in total electric power due to the electric power supply to the heater at the time of high duty that consumes a large amount of electric power, and it is possible to use the low capacity power source. Then, the process of block 318 described above is performed.

That is, the printing corresponding to the drawing area 1 (or 3) is executed in the first scanning, and the printing corresponding to the drawing area 2 (or 4) is executed in the second scanning, or the first scanning is executed. The dot corresponding to the black portion of the zigzag pattern shown in FIG. 9 is printed by the scanning of, and the dot corresponding to the white portion is printed by the second scanning.

In the above-mentioned block 310, FIG.
Although the logical sums of the respective segments in the two drawing areas are calculated as shown in, the logical product may be calculated instead, and if the result is not 0, printing may be performed twice. In this case, the condition is relaxed compared to the above example, that is, the case of the logical sum,
When the same segment in both areas has high duty, the scanning is performed twice.

Various other logical or arithmetic operation combinations are possible, and all of them are included in the scope of the present invention.

As described above, according to the third embodiment, the power consumption in the local area in each drawing area can be determined, so that the peak power supply design of the power supply can be further reduced and the power supply of the power supply can be reduced. Further miniaturization and cost reduction are further promoted.

In each of the above-described embodiments, the case where the recording head used is 128 nozzles and the maximum number of print buffers capable of simultaneously recording is two has been described. However, as will be easily understood by those skilled in the art, The invention can be applied to a longer recording head such as 256 nozzles, 512 nozzles, or 1024 nozzles. In such a case, the number of print buffers that can be recorded simultaneously is 4 and 8 respectively.
When the effective pixel rate corresponding to each section exceeds a predetermined number or more and exceeds a predetermined value, it is effective to print the contents of those print buffers by a plurality of scans.

Further, in the embodiment, the height of one print buffer is set to 64 dots for convenience of explanation, but it will be easily understood that the present invention is not limited to this.

According to each of the embodiments described above, basically, the effective pixel number of the print buffer is obtained, the effective pixel rate is calculated from the number, and when the value is equal to or more than a predetermined value, the print It can be controlled to prohibit the control of the heat retention heater during buffer printing. Further, another embodiment has a plurality of print modes in which a predetermined print area corresponding to the effective print width of the print head is printed by a single scan or a plurality of scans. Then, the number of effective pixels in the print buffer is counted before printing, the effective pixel ratio to the total number of pixels in the buffer is obtained, and based on the effective pixel ratio (or a value or code related thereto), One of the print modes can be selected. In this way, the control of the heat retention heater is permitted by dividing the printing at high duty into a plurality of scans. Alternatively, the heat retention heater control is prohibited only in the multiple scan mode and when the duty is higher than a predetermined value.

Further, in another embodiment of the present invention, one print buffer is divided into a plurality of sections, the effective pixel ratio in each section is obtained, and the effective pixel ratios (or the values or symbols related thereto) are calculated. ) And selecting one of the plurality of print modes.

Further, in another embodiment of the present invention, a plurality of print buffers are prepared, each print buffer is divided into a plurality of sections in the same manner as described above, and each of the plurality of buffers which may be simultaneously recorded is divided. One of the plurality of print modes is selected based on the result of a predetermined arithmetic operation or logical operation of the effective pixel ratio (or the value or sign related thereto) in the partition. Further, depending on the effective pixel ratio of each segment, the permission or prohibition of the control of the heat retention heater during printing of the line is determined.

As a result, in the recording apparatus using the long recording head, the effective pixel ratios of a plurality of print buffers corresponding to the drawing areas which may be recorded next before being actually recorded on the recording paper. By appropriately controlling the print mode based on the result of the investigation, it is possible to provide a printer that can use a low-power and low-cost power supply.

Further, it is determined from the effective pixel ratio of each print buffer or its segment whether ON / OFF control of the heat retaining heater is enabled during printing of the content, and voltage drop due to superposition of the heat retaining heater at high duty is determined. It is possible to provide a printer which can prevent such a problem, and which can output a high-quality print output with a small change in density despite using a low power and low cost power supply. As a result, for an image having a low effective pixel rate such as a text which is frequently generated, it is possible to print at high speed by using all the recording elements of the long recording head, and a graphic or an image having a high effective pixel rate can be obtained. With respect to the above, it is possible to provide a recording method and apparatus capable of flexibly coping with a plurality of scans.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device.

Needless to say, the present invention can also be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0088]

As described above, according to the present invention, in a recording apparatus that performs recording by sequentially scanning a recording head having a plurality of recording elements in a direction perpendicular to the recording paper conveyance direction, recording is performed before recording. In order to measure the effective pixel ratio of information, even when printing of low density such as text data and printing of high density such as graphics data or image data are mixed in one recording, The optimum heat retention drive control can be performed for each printing. Therefore, it is possible to effectively prevent an unnecessary increase in power consumption when the recording head is driven, and it is possible to provide a recording apparatus and method that maintain high printing quality and achieve low power consumption.

Furthermore, by measuring the effective pixel ratio for each line, effective power consumption reduction can be achieved with simple control.

Furthermore, by dividing the storage means into a plurality of sections and measuring the effective pixel ratio in each of the plurality of sections thus divided, it is possible to achieve a finer reduction in power consumption.

[0091]

[Brief description of drawings]

FIG. 1 is an external perspective view showing the outline of the configuration of an inkjet printer IJRA that is a typical embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control circuit of the inkjet printer IJRA shown in FIG.

FIG. 3 is a diagram showing a configuration example of a recording head used in the present invention.

FIG. 4 is a diagram showing an example of a print buffer configuration in a recording apparatus according to an embodiment of the present invention.

5 is a diagram showing how characters to be actually printed are recorded in the print buffer shown in FIG. 4;

FIG. 6 is a diagram showing an overall configuration of a heater board in a recording head in the present embodiment.

7 is a partially enlarged view of a heater board in the recording head shown in FIG.

FIG. 8 is a diagram showing temperature control of the print head of the present embodiment.

FIG. 9 is a diagram illustrating an example of a printing method according to the present exemplary embodiment.

FIG. 10 is a diagram showing an example of temperature adjustment control of a recording head according to a second embodiment of the invention.

FIG. 11 is a diagram showing an example of temperature control of a print head according to a third embodiment of the invention.

FIG. 12 is a diagram showing an example of division of a print buffer in the third embodiment.

13 is a diagram showing an example of a density flag register in which a result of indexing the effective pixel ratio of each section divided into 16 of each drawing area of FIG. 12 with 0 or 1 is stored.

FIG. 14 is a drawing area 1 and 2 shown as an example in FIG.
6 is a diagram showing the contents of a density flag register corresponding to FIG.

[Explanation of symbols]

43 128 heating elements 42 Temperature sensor using meandering pattern of aluminum 45 Pad for wire bonding 48 Heat insulation heater 1700 Interface 1701 MPU 1702 Program ROM 1703 Dynamic type RAM 1704 Gate array 1708 Recording head

Claims (10)

[Claims] 1. A recording apparatus for performing recording by sequentially scanning a recording head having a plurality of recording elements in a direction perpendicular to a recording paper conveyance direction, and a heater means for keeping the recording head warm, and recording for at least one line. Storage means capable of storing information, measuring means for measuring the effective pixel rate of the record information stored in the storage means, and in the storage means when the effective pixel rate measured by the measuring means is a predetermined value or less A recording apparatus, comprising: a heater control unit that permits a heat retention drive control of the heater unit during recording of recording information. 2. The recording apparatus according to claim 1, wherein the measuring unit measures the effective pixel ratio of the recording information for one line of the storage unit. 3. The recording apparatus according to claim 1, wherein the measuring unit divides the storage unit into a plurality of sections and measures an effective pixel ratio in each of the plurality of divided sections. 4. The heater control means permits warming drive control of the heater means during recording of the record information stored in the storage means when the effective pixel ratios measured by the measuring means in each section are all less than or equal to a predetermined value. The recording apparatus according to claim 3, wherein: 5. The recording apparatus according to claim 1, wherein the recording head is an inkjet recording head that ejects ink to perform recording. 6. The recording head is a recording head for ejecting ink by utilizing thermal energy, and is provided with a thermal energy converter for generating thermal energy applied to the ink. Item 5. The recording device according to item 5. 7. A recording method in a recording apparatus for performing recording by sequentially scanning a recording head having a plurality of recording elements in a direction perpendicular to a conveyance direction of a recording paper, wherein recording information to be recorded by the recording head is recorded. A recording method, comprising: measuring an effective pixel ratio, and driving and controlling a heater for keeping a temperature of a recording head during recording of the recording information when the measured effective pixel ratio is equal to or less than a predetermined value. 8. The recording method according to claim 7, wherein the effective pixel ratio of the recorded information is measured by measuring the effective pixel ratio of the recorded information for one line. 9. The measurement of the effective pixel rate of the recording information is performed by dividing the recording information into a plurality of sections and measuring the effective pixel rate in each of the plurality of divided sections. Recording method described. 10. The recording according to claim 9, wherein the heater activation control permits the heat retention drive control of the heater when all of the measured effective pixel ratios in each section are equal to or less than a predetermined value. Method.