JPH04241954A - Image recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the generation of irregularity in a dot forming state due to the difference of use frequency between respective nozzle heaters in an image recording apparatus recording an image by operating a plurality of the nozzle heaters corresponding to a plurality of dots. CONSTITUTION:Preheating energy of a degree forming no dot is applied to a nozzle heater generating heat not even once during the one-line recording operation of an image during the period transferring from one-line recording operation to the next one-line recording operation.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is an image recording system that controls the heat generation of a plurality of heating elements corresponding to a plurality of dots, thereby recording an image line by line using the heat generated by each heating element. Regarding equipment.

0002

2. Description of the Related Art This type of image recording apparatus includes, for example, an inkjet type apparatus in which ink is ejected from nozzles. In this type of recording device, if the inkjet head is left in a normal environment for a long time, the ink at the tip of the nozzle dries, making it difficult to eject ink from the nozzle, resulting in recording failure. In some cases, the ink becomes unclear and, as a result, the ink stops being ejected (hereinafter referred to as sticking). For this reason, a protective capping means is provided to prevent the surface of the head from drying out.
A device has been proposed to prevent ink from evaporating at the tip of a nozzle.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned recording device, when there is a large difference in the frequency of use of the large number of heating elements corresponding to the individual nozzles of the inkjet head, Nozzles corresponding to heating elements that have been used extremely infrequently and have not been used for a long time will be exposed to the normal environment for a long time, so the ink at the tip of the nozzle may dry up. However, there still remains the problem that the recording becomes unclear and the above-mentioned sticking occurs.

[0004] Furthermore, in order to avoid such problems,
An apparatus has been devised that performs an operation of ejecting ink from all nozzles once after printing a predetermined number of sheets (hereinafter referred to as idle ejection). However, when such devices continuously record a number of pages exceeding a predetermined number of pages over a long period of time, the recording time is delayed by the amount of blank ejection for each predetermined number of pages, and the important part of the recording device is A new problem arises in that the recording speed, which is performance, is greatly adversely affected.

[0005] Furthermore, in a recording device using a thermal head equipped with a large number of heat generating resistors as heating elements, temperature differences occur due to differences in the frequency of use of each of the large number of heat generating resistors during recording operation. Dots corresponding to heating resistors that are used extremely infrequently may become unclear.

[0006] As described above, the conventional printing apparatus that performs printing by controlling the heat generation of a plurality of heating elements has a problem in that dots corresponding to heating elements that are used less frequently become unclear.

It is an object of the present invention to solve the above-mentioned conventional problems, to avoid blurring of dots corresponding to heating elements that are used infrequently, and to prevent ink from sticking in the inkjet system, thereby improving recording performance. To provide an image recording device capable of performing clear and reliable recording without reducing speed.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the image recording apparatus of the present invention has a plurality of heating elements corresponding to a plurality of dots in the recording head, and heat generation of each heating element is controlled. In an image recording apparatus that records an image line by line using the heat generated by each heating element, there is provided a detection means for detecting a heating element whose heating is not controlled during the recording operation of one line, and a detection means for detecting a heating element whose heating is not controlled during the recording operation of one line, and A supply means capable of supplying preheat energy to generate heat to an extent that does not lead to the formation of dots in the element, and a detection means capable of detecting the preheat energy during transition from one line recording operation to the next one line recording operation. and a control means for supplying the preheat energy of the supply means to the heated heating element.

[0009]

[Operation] The image recording apparatus of the present invention generates heat to the extent that does not lead to the formation of dots each time one line of recording operation is completed, to the heating elements that are not controlled to generate heat during one line of recording operation. preheat drive by supplying energy to

0010

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

[Example 1] Figures 1, 2, 3 and 4
FIG. 1 is a diagram for explaining a first embodiment of the present invention. Further, FIG. 8 is a perspective view showing an example of an inkjet recording apparatus to which the present invention is applicable.

First, the schematic structure of the recording apparatus shown in FIG. 8 will be explained.

In FIG. 8, reference numeral 101 denotes an inkjet recording head equipped with an ink discharge port for discharging ink to perform recording, 122 a carriage for scanning the recording head 101 in the main scanning direction, and 123 a pulse motor (123) for driving the carriage 122. 124 is a drive belt that transmits the driving force of the CR motor 123 to the carriage 122, 125 is a carriage guide shaft, 126 is a conveyance roller that feeds the recording material 131 to be recorded in the sub-scanning direction, and 127 is a conveyance belt. A pulse motor (LF motor) drives the roller 126, 128 is an LF motor 127
and a control circuit for driving and controlling the CR motor 123 according to a recording command; 129 is a control circuit 128;
The flexible cable 130 that sends the recording signal to the recording head 101 is a sheet guide plate.

Next, FIG. 4 is a schematic diagram of the recording head 101 used in this embodiment.
02, a nozzle heater (heating element) 57, an electrode 104, a nozzle wall 105, and a top plate 106. Recording ink 112 is supplied to the recording head 10 from a liquid storage chamber (not shown) through a liquid supply pipe 107.
1 common liquid chamber 108. The liquid (ink) 112 supplied into the common liquid chamber 108 is supplied into the nozzle 110 by capillary action, and is stably held by forming a meniscus on the orifice surface at the tip of the nozzle. Then, by energizing the nozzle heater 57, the liquid on the heater surface is heated, a bubbling phenomenon due to film boiling occurs, and the energy of the bubbling causes the orifice surface 111 to be heated.
Droplets are ejected from. The nozzle heater 57 is connected to the drive I
Driven through electrode 104 by C103. The drive IC 103 controls the nozzle heater 57 according to the ejection signal input from the ejection signal control circuit shown in FIG.
drive for a specified period of time.

With this configuration, the nozzle density can be increased to 16
It becomes a high-density nozzle piping such as nozzle/mm, and 12
A serial type inkjet recording head 101 with 8 nozzles or 256 nozzles is configured.

In FIG. 1, 11 is a counter that generates an address designation signal for the RAM 12, and a synchronization signal LS
When NC is at high level “H”, it is cleared to “0”, and while the line section signal LE is “H”, the image clock VCK
Count the rising edge of . These signals LSNC,L
E and VCK will be described later. The RAM 12 stores image data VD in accordance with the address designation signal generated by the counter 11. The image data VD is transferred to the RAM through an OR gate 13 and an AND gate 25.
12. In this embodiment, the counter 11 has 8 bits and the RAM 12 has a minimum of 256 bits, corresponding to the recording head 101 having 256 nozzles.

The OR gate 13 takes the logical sum of the output of the RAM 12 and the image data VD, and outputs the result to the AND gate 25. The AND gate 25 outputs the image data VD output from the OR gate 13, the page section signal PE, and the scan section signal B.
PE and their signals PE and BPE
The image data VD is supplied to the RAM 12 only in the valid section of the image where both are "H". Therefore, the signal P
When E and BPE are in the invalid "L" level section,
No image data is supplied to the RAM 12, and the RAM 12 is cleared. Signals PE and BPE will be described later.

The output signals of the image data VD and the RAM 12 are sent to the corresponding flip-flops 14 and 1, respectively.
5, and the former is input to an AND gate 18, and the latter is inverted by an inverter 24 and then input to an AND gate 19 as a signal MD. Each of the AND gates 18 and 19 outputs the 7-bit data latched in the latch circuits 16 and 17 to the selector 20 as DD data and HD data only when the input signal VD and signal MD are "H". do. The latch circuits 16 and 17 are connected to a CP (not shown).
It is connected to the U bus and latches data on the CPU bus while the CPU write signal WR is "H".

The selector 20 selects an AND gate 1 according to the states of a signal BPE and a signal PRHE, which will be described later.
This is a 7-bit selector circuit that selects and outputs one of the output signal DD of the AND gate 19 and the output HD of the AND gate 19,
Output the data according to the table below.

[0020]

[Table 1]

The output of the selector 20 is synchronized with the image clock VCK by the flip-flop 21, and then pulse width data P defining the drive time of the nozzle heater 57 is output.
As a WD, the head driver 2 in the drive IC 103
3 is input. Further, a timing generation circuit 22 is connected to the head driver 23, and as described later, this timing generation circuit 22 generates a signal from the recording head 101 based on the signals LSNC, LE, and the image clock VCK.
Nozzle drive timing signals (signals ECK, EI, LA
T and SCK).

FIG. 2 is a block diagram of the inside of the head driver 23. As shown in FIG. In the figure, circuits 201, 202,
... are circuits that drive the nozzle heaters 57 in the corresponding nozzles, and in the case of this embodiment, 256 nozzles are formed, so the same circuit as the circuit 201 is used to drive the nozzle heaters 57 in the corresponding nozzles.
Six circuits are built into the head driver 23. Therefore, in the following, the circuit 201 will be explained as a representative.

First, 7-bit pulse width data PWD input from the ejection signal control circuit shown in FIG. 1 is input to the flip-flop 51. The output of this flip-flop 51 is input to the flip-flop 51 of the circuit 202, and the output of the flip-flop 51 of the circuit 202 is further input to the flip-flop 51 of the circuit 203. Each flip-flop 51 of the circuits 201, 202, . . . connected in this manner is used as a shift register that shifts data PWD every time a shift clock SCK is input. Further, the output of the flip-flop 51 is input to a latch circuit 52. This latch circuit 52 latches and outputs input data when the latch signal LAT is "H". The data latched by the latch circuit 52 is then loaded into the counter 53.

The counter 53 is configured so that the input signal at the terminal E is “H”.
”, this is a down counter that counts down the loaded value every time the clock ECK (to be described later) rises, and loads the data when the input signal of the terminal E is “L”.The counter 53 starts counting down. When the count value reaches "0", a carry is output.

The carry output of the counter 53 and a signal EI, which will be described later, are input to a flip-flop 54. This flip-flop 54 sets the Q output to "H" when an "H" signal is input to the set terminal S, and sets the Q output to "L" when an "H" signal is input to the reset terminal R. This is an R-S flip-flop. The output of this flip-flop 54 is passed through a buffer 55 to a transistor 56.
is input. This transistor 56 is a transistor that drives the nozzle heater 57, and controls ejection/pause of ink from the nozzle by turning on/off the power supplied from the nozzle heater power supply 58, and also controls the output pulse of the flip-flop 54. The driving time of the nozzle heater 57 is controlled according to the width.

Next, the timing of each signal will be explained using FIG.

First, the signal LE is a line section signal indicating a valid section of the image data VD in one line of nozzles arranged perpendicularly to the scanning direction of the head.
The section of "H" is a valid section of the image data VD in one line.

Signal PE is a page section signal indicating a valid section of image data VD in one page, and the "H" section of signal PE is defined as the size of the recording area in one page.

Signal BPE is image data V during one scan when scanning is performed multiple times to form an image of one page.
This is a scanning section signal indicating the effective section of D. therefore,
Page section signal PE and scanning section signal BPE are "H"
During the effective period, ink is ejected only when the line period signal LE is "H".

Signal PRHE is a preheat drive signal that defines an effective period for preheat driving, and preheat driving is performed during the "H" period of signal PRHE. Moreover, this preheat drive signal PRHE is
The scanning interval signal BPE becomes "H" during the "L" interval, and the scanning period signal BPE becomes "H" for the preset number of lines (in this embodiment, 2
When the preheat drive is performed by the amount of line), it becomes "L". This is achieved by counting the rising edges of the line interval signal LE.

Signal VCK is a video clock, as shown in FIG.
All ejection signal control circuits are based on this video clock VC.
It operates in synchronization with K.

The signal LSNC is a synchronizing signal for the line section signal LE, and becomes "H" only one clock before the line section signal LE becomes "H".

The image data VD is a binary video signal, and control is performed so that ink is ejected when it is "H" and ink is not ejected when it is "L". Then, according to this image data VD, pulse width data PWD is controlled as shown in the following table.

[0034]

[Table 2]

Signal SCK, signal LAT, signal EI, and signal ECK are control signals generated by timing signal generation circuit 22.

The signal SCK is a shift clock for shifting the pulse width data PWD in the flip-flops 51 of each circuit 201, 202, . . . and is output only during the valid period when the line period signal LE is "H" be done. Further, the signal LAT is a latch signal that causes the latch circuit 52 to latch the pulse width data PWD shifted by the flip-flop 51 of each circuit 201, 202, . . . In the case of this embodiment, the line section signal LE is It is output after becoming invalid "L". Further, the signal EI is a drive signal that instructs each nozzle to start ejecting ink. Further, the signal ECK is a clock input to the clock terminal of the counter 53, and its frequency is equal to the pulse width data PWD.
It is related to the resolution of the pulse width t. In the case of this example,
The frequency of this signal ECK is 2MHz (0.5μsec)
It is.

Next, the operation will be explained.

Each time the counter 11 counts the number of nozzles for one line, the counter 11 is set to "0" by the line synchronization signal LSNC.
” will be cleared. Therefore, the count value of the image clock VCK output by this counter 11 corresponds to the nozzle number of the recording head 101 and becomes an address designation signal for the RAM 12. Therefore, the image data VD inputted from an image input device (not shown) is logically summed with the output of the RAM 12 by the OR gate 13, and the page section signal PE and the scanning section signal BPE are both in the valid section of "H". Under certain conditions, it is written to the same address in the RAM 12 again. Therefore, signals PE and B
If the image data VD for each nozzle becomes "H" even once in each scan when both PE are "H",
The recorded content of the address corresponding to that nozzle in the RAM 12 becomes "H".

After one scan of recording is completed in the RAM 12, when no image is to be formed, the inverter 24
The output signal MD becomes "H" only in the portion corresponding to the nozzle that did not print even once during the previous scan (hereinafter referred to as an unused nozzle). The signal MD corresponding to the determination signal for the unused nozzle controls the AND gate 19, so that the 7-bit pulse width data previously set in the latch circuit 17 is input to the selector 20 as pulse width data for the unused nozzle. be done. Here, the pulse width data set in the latch circuit 17 is data for preheating by driving the nozzle heater 57 for a short time to the extent that no ink is ejected, and in this embodiment, the driving time is about 4 μsec. The corresponding number is "40H".

Furthermore, when no image is being formed, no image data is supplied from the gate 25 to the RAM 12. Therefore, the stored contents of the RAM 12 corresponding to the addresses generated by the counter 11 are sequentially cleared to "L" in preparation for determination of unused nozzles in the next scan or next page. When the RAM 12 is cleared, that is, when the page section signal PE or the scanning section signal BPE is "L", the line section signal LE for multiple lines is input to the RAM 12, and the stored contents of all addresses in the RAM 12 are reliably " Clear to L”.

On the other hand, during one scan, the image data V
By controlling the AND gate 18, the ejection pulse width data previously set in the latch circuit 16 is inputted to the selector 20 as print data. Here, the pulse width data set in the latch circuit 16 is
This data corresponds to the driving time of the nozzle heater 57 for ejecting ink, and in this embodiment, it is "70H" which corresponds to about 7 μsec.

The selector 20 receives the signal PE as described above.
and PRHE to selectively output data from AND gate 18 or 19. That is,
During a printing operation, data "70H" is output to nozzles that eject ink, and data "00H" is output to nozzles that do not eject ink. On the other hand, when preheat driving is performed during non-printing operation, data "40H" is output to unused nozzles that did not eject ink even once during one line recording operation of an image by one scan, and Data "00H" is set for a nozzle that ejected ink even once during the scanning operation of recording one line of an image.
Output. These data "00H", "70H" and "40H" are input to the flip-flop 21 as pulse width data PWD.

Then, pulse width data PW for the number of nozzles
D is shifted by the flip-flop 51 in the head driver 23 based on the shift clock SCK, then latched by the latch circuit 52 corresponding to each nozzle, and then loaded into the counter 53. The counter 53 counts the rise of the clock ECK using the drive signal EI as a trigger, and outputs a carry signal after counting by the value of the loaded pulse width data PWD. That is, the counter 53 calculates that the pulse width data PWD is "
When it is "70H", a carry is output after a count time of 7μsec, when it is "40H", a carry is output after a count time of 4μsec, and when it is "00H", a carry is output without counting. become.

While the counter 53 is counting, the output Q of the flip-flop 54 becomes "H", and during this time, the nozzle heater 57 receives power from the nozzle heater power supply 58 due to the action of the buffer 55 and the transistor 56. is supplied.

In the end, for unused nozzles that did not eject ink even once during the recording operation of one line of an image by one scan, the recording of one line by one scan is performed at the time of non-printing after each scan, that is, one line is recorded by one scan. During the transition from the operation to the next recording operation of one line by one scan, the nozzle heater 57 is driven for a short time of 4 μsec during which no ink is ejected, to appropriately activate the ink. Therefore, ink sticking can be prevented without reducing the recording speed. [Embodiment 2] Next, a second embodiment of the present invention will be described using FIGS. 5 and 6.

FIG. 5 shows counter 1 in FIG.
1, a RAM 12, and an OR gate 13; FIG. In the figure, the same components as those in the first embodiment are given the same reference numerals and signal names, and their explanation will be omitted.

In FIG. 5, a shift register 31 is a shift register that shifts image data VD sent out as ink ejection data in the order of nozzle numbers in synchronization with a video clock VCK. 2
It has a 256-stage shift register corresponding to a 56-nozzle recording head. Each of the outputs of this shift register 31 is input to a gate circuit 32. This gate circuit 32 includes OR gates 32a and AND gates 32 for 256 nozzles corresponding to the number of outputs of the shift register 31.
The outputs of the shift registers 31 are input to one input terminal of the corresponding OR gates 32a. Further, the outputs of the OR gates 32a are inputted to one input end of the corresponding AND gates 32b,
The outputs of the AND gates 32b are respectively input to the latch circuits 33. Furthermore, the scanning period signal BPE is input to the other input terminal of the AND gate 32b.

33 is 256 from AND gate 32b
This is a latch circuit that latches data for the nozzles.The output of this latch circuit 33 is input to the other input terminal of the corresponding OR gate 32a, and a shift register that converts 256-bit parallel data into serial data. 34. The output of the shift register 34 is inverted by the inverter 24, and then the signal N
It is input as D to an AND gate 19 similar to that in FIG.

The latch circuit 33 and the shift register 34 latch data when the latch signal LEN, which will be described later, is "H", and the gate circuit 32 outputs the logic between the output of the latch 33 circuit and the output of the shift register 31. The sum is calculated and the result is repeatedly output to the latch circuit 33 while the scanning period signal BPE is in the valid period of "H". Therefore, in the latch circuit 33, the data corresponding to the nozzle that ejected ink even once during one scan is "
The data corresponding to the nozzles that did not eject ink once during one scan becomes "H", and when the scanning period signal BPE is an invalid section of "L", all data becomes "L". As a result, the contents of the latch circuit 33 are cleared.

FIG. 6 is a timing chart explaining the latch signal LEN. This latch signal LEN goes "H" only one clock before the line section signal LE goes "L".
The data is held in the latch circuit 33 and shift register 34 during this "H" period.

In addition to the effects of the first embodiment described above, this embodiment has the advantage that since it can be constructed entirely of gate circuits, it can be easily formed into a chip, making it possible to realize miniaturization and cost reduction of the circuit.

[Third Embodiment] In the first embodiment described above, data is set from the CPU pulse in order to set the pulse width data PWD, but other setting methods may be adopted.

FIG. 7 shows an example of a configuration in which pulse width data PWD is set using a DIP switch. In the figure, switches 35 and 36 are 7-bit dip switches for inputting ink ejection data DD and preheat drive data HD, respectively. In the case of this embodiment, since the switches 35 and 36 themselves have a memory function for input data, even if the CPU (not shown) goes out of control, input of pulse width data PWD that would destroy the nozzle heater 57 is possible. doesn't happen.

[0054] In Examples 1 to 3 above, an inkjet type recording apparatus has been described, but the present invention is not limited to the inkjet type in any way, and can be applied to, for example, a recording apparatus using a thermal head. It's okay. When the present invention is applied to a recording device using a thermal head, among the many heating elements in the thermal head, those that are used less frequently are preheated to suppress the temperature difference with other heating elements. , will stabilize the image well.

(Others) As described in the above-mentioned embodiments, the present invention is particularly applicable to inkjet recording methods, such as means for generating thermal energy as energy used to eject ink (for example, electrothermal conversion). This provides an excellent effect in a recording apparatus that uses the thermal energy to cause a change in the state of the ink. According to such a method, recording density can be increased,
This is because high definition can be achieved.

For its typical configuration and principle, see, for example, US Pat. Nos. 4,723,129 and 4,740.
Preferably, it is carried out using the basic principles disclosed in the '796 specification. This method is the so-called on-demand type.
It is applicable to both continuous types, but in particular, in the case of on-demand type, it is applicable to the electrothermal converter placed corresponding to the sheet holding the liquid (ink) or the liquid path. , by applying at least one drive signal that corresponds to recorded information and provides a rapid temperature rise exceeding nucleate boiling, the electrothermal transducer generates thermal energy to produce film boiling on the thermally active surface of the recording head. liquid (ink) that corresponds one-to-one to this drive signal.
This is effective because it can form air bubbles inside. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, making it possible to eject liquid (ink) with particularly excellent responsiveness. This pulse-shaped drive signal is described in US Pat. No. 4,463,359 and US Pat.
345262 are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

[0057] In addition to the configuration of the recording head that is a combination of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44 disclose a configuration in which a heat acting part is arranged in a bending region.
A configuration using the specification of No. 59600 is also included in the present invention. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The effects of the present invention are also effective even with a configuration based on Japanese Patent Application Laid-open No. 138461/1985 which discloses a configuration corresponding to the discharge section. That is, regardless of the form of the recording head, according to the present invention, recording can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by the recording apparatus. Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally.

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

Furthermore, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. . Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

Regarding the type and number of recording heads to be mounted, for example, in addition to a single head that corresponds to a single color ink, there are also systems that correspond to a plurality of inks of different recording colors and densities. A plurality of them may be provided. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode for only a mainstream color such as black, but may also be a recording mode in which the recording head is configured integrally or in a combination of multiple colors, The present invention is also extremely effective for devices equipped with at least one full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid, but ink that solidifies at room temperature or below, softens or liquefies at room temperature, or inkjet method. In general, the temperature of the ink itself is adjusted within the range of 30°C to 70°C to keep the viscosity of the ink within the stable ejection range. Any eggplant is fine. In addition, the temperature increase caused by thermal energy can be actively prevented by using the energy to change the state of the ink from a solid state to a liquid state, or ink that solidifies when left standing is used to prevent ink evaporation. In any case, the ink is liquefied by applying thermal energy in accordance with the recording signal, and the liquid ink is ejected, or the ink has already begun to solidify by the time it reaches the recording medium. The present invention is also applicable when using ink that is liquefied only by energy. The ink used in such cases is disclosed in Japanese Patent Application Laid-Open No. 54-56847 or Japanese Patent Application Laid-Open No. 60-1989.
As described in Japanese Patent No. 71260, the material may be held in a liquid or solid state in a porous sheet recess or through-hole and face an electrothermal converter. In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

In addition, the recording device of the present invention can be used as an image output terminal for information processing equipment such as a computer, as well as a copying device combined with a reader or the like, and even a facsimile device having a transmitting and receiving function. It may also be something that is harvested.

[0064]

As explained above, the image recording apparatus of the present invention detects a heating element that has not been subjected to heat generation control even once during the recording operation of one line, and Each time a line recording operation is completed, energy is supplied to generate heat that does not lead to the formation of dots, and the preheat drive is performed. By effectively utilizing the time during the transition, the heating element can be preheated.

As a result, clear images can always be stably recorded without reducing the recording speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a head driver control circuit in a first embodiment of the present invention.

FIG. 2 is a block diagram of a circuit within the head driver shown in FIG. 1;

FIGS. 3A and 3B are timing charts for explaining the operation of the first embodiment of the present invention, respectively.

FIG. 4 is an enlarged sectional view of the recording head in the first embodiment of the invention.

FIG. 5 is a block diagram showing main circuitry in a second embodiment of the present invention.

FIG. 6 is a timing chart for explaining the operation of the second embodiment of the present invention.

FIG. 7 is a block diagram of a control circuit for a head driver in a third embodiment of the present invention.

FIG. 8 is a perspective view showing an example of an inkjet recording apparatus to which the present invention can be applied.

[Explanation of symbols]

11 Counter 12 RAM 13 OR gate 20 Selector 22 Timing signal generation circuit 23 Head driver 53 Counter 54 Flip-flop 56 Drive transistor 57 Nozzle heater (heating element) 58 Power supply 101 Recording head 103 Drive IC 104 Electrode 108 Common liquid chamber 110 Nozzle 112 Recording ink

Claims (3)

[Claims] Claim 1: The recording head has a plurality of heating elements corresponding to a plurality of dots, and by controlling each heating element to generate heat, the image recording operation for each line is performed using the heat generated by each heating element. In an image recording apparatus that performs a recording operation, a detection means for detecting a heating element whose heat generation is not controlled during one line recording operation, and supplying preheat energy to each heating element to generate heat to an extent that does not lead to dot formation. and a control means for supplying the preheat energy of the supply means to the heating element detected by the detection means during transition from one line of recording operation to the next one line of recording operation. An image recording device comprising: 2. The image recording apparatus according to claim 1, wherein the recording head is an inkjet recording head that discharges ink from an ejection port using heat generated by the heating element. 3. The image recording apparatus according to claim 2, wherein the inkjet recording head includes, as the heating element, a means for generating thermal energy that causes film boiling in the ink for ejecting the ink. .