JPH07125215A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To enable normal ejection by uniformizing the temp. of the ink in a recording head by providing a means controlling the temp. of the ink in the liquid part and common liquid chamber of a recording head by controlling the driving due to a heater driving means. CONSTITUTION:A cap member 5022 capping the front of a recording head is supported by a support member 5016. A suction means 5015 has function to reduce the pressure in the cap member to suck ink and the sucked ink is guided to the outside of the cap through the opening 5023 of the cap. A cleaning blade 5017 is a member capable of moving a blade 5019 before and behind and supported by a main body support plate 5018. As the blade 5017, a known cleaning blade can be adapted. A temp. sensor and a humidity sensor are provided to detect the temp. and the humidity of the atmosphere where an ink jet recording apparatus is placed and the temp. of a recording head can be estimated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to temperature control of ink in a recording head.

[0002]

2. Description of the Related Art A recording device in a printer, a copying machine, a facsimile, etc., which is used together with a computer, a word processor or the like, or is used alone, records on a recording material such as paper or a plastic thin plate based on image information. Is configured to do. Such a recording apparatus can be classified into an inkjet method, a wire dot method, a thermal method, a laser beam method, and the like, depending on the recording method.

Among them, the ink jet method is one in which recording is performed by ejecting ink from a recording head onto a recording material, and it is possible to record a high-definition image at a high speed. It has the advantages that it can be recorded without requiring pre-processing, and that it is a non-impact system that produces less noise and that it is easy to record color images using multicolor inks. ing.

The temperature of the recording head used in the ink jet recording apparatus as described above changes depending on the environment in which the recording apparatus is used and the ejection driving conditions. In such a case, the amount of ink ejected onto the recording material often changes. For example, as the ejection driving condition, the ejection amount is increased in the high duty recording, and the ejection amount is decreased in the low duty recording. When the ink ejection amount changes in this way, the density of the image printed on the recording material is somewhat uneven, and the recording quality is impaired.

In order to prevent such a problem, in the conventional ink jet recording apparatus, the temperature sensor provided in the recording head is used to control the temperature of the recording head by a closed loop, or energy input to the recording head. The head temperature is known by a temperature calculation method for calculating and estimating the head temperature from the above, and a method of controlling the temperature of the print head within a desired range by heating the print head by a temperature control heater based on the detected temperature is adopted. It was

Of the above temperature control methods, the method of calculating and estimating the temperature is roughly as follows: The temperature of the object heated by the energy input by the temperature control heater or the like is lowered every time a unit time elapses. Is set in advance, and the current temperature of the object is estimated by calculating the sum of how many times the temperature that has risen per unit time in the past is decreasing at the present time.

As the heater used for the temperature control, there is a heater for heating formed on a portion of the recording head substrate which does not come into direct contact with ink, or a heater used for ejecting ink, that is, an ejection heater for an ink jet recording head. It was used for both.

In the case of using the conventional temperature control heater as described above, this heater is formed in a portion which does not come into contact with ink other than the portion corresponding to the common liquid chamber on the head substrate (made of Si or the like). Therefore, the ink is heated via the head substrate. Further, the heat from the temperature control heater is radiated to the contact members other than the ink and the air via the head substrate, the ratio of the heat given to the ink becomes very low, and the heating efficiency of the ink becomes low.

By the way, the temperature change in the liquid passage and in the common liquid chamber due to the heating of the temperature control heater provided in a portion which does not come into direct contact with the ink tends to be as shown in FIG.

That is, as is apparent from FIG. 7, the temperature of the ink in the liquid passage rapidly rises due to heating by the heater, while the temperature in the common liquid chamber rises slightly more gently than in the liquid passage. To go.

Here, when heating of the control heater is stopped and printing is started, the temperature is decreased immediately after that, but this temperature decrease is gentle as compared with the temperature increase. This is because heating of the ink in the liquid path by the ejection heater is added. However, the ink temperature in the liquid path immediately before the end of printing is lower than immediately after the start of printing. This is because the ink in the common liquid chamber is supplied into the liquid passage along with the printing, but the ink in the common liquid chamber is not heated as much as in the liquid passage by the temperature control heater.

Further, when the discharge heater is used as an ink heating heater, the temperature changes in the liquid passage and in the common liquid chamber tend to be as shown in FIG.

In this case, the difference in the temperature gradient and the absolute value of the temperature of the ink in the liquid passage and in the common liquid chamber becomes more remarkable than in the case of heating by the temperature control heater not in contact with the ink.

[0014]

As described above, the response to the heating of the ink in the liquid passage is good, and the relationship between the heating characteristics and the ink in the common liquid chamber causes the ejection just after the start of printing and immediately before the end of printing. There are relatively large differences in quantity. Further, since the ink in the liquid passage is intensively heated, the viscosity of the ink in the common liquid chamber is still high even if the viscosity of the ink in the liquid passage becomes low, and if the ink is continuously ejected, the ink supply will not catch up. It was sometimes gone.

Even when the discharge heater is used for controlling the ink temperature, only the ink in the liquid passage is locally heated, while the ink in the common liquid chamber is hardly heated, and the contents of the liquid passage after the start of discharge When the integrated ink is consumed, the temperature of the ink that is supplied from the common liquid chamber next time is almost the same as before heating, causing uneven printing in the row direction and the difference in ink viscosity between the liquid passage and the common liquid chamber. As a result, a problem occurs such that the ink cannot be supplied smoothly.

The present invention has been made in order to solve the above-mentioned conventional problems, and an object thereof is to make the ink temperature in the recording head uniform so that normal ejection is always possible and density unevenness is maintained. An object of the present invention is to provide an inkjet recording device capable of recording a high-quality image without a defect.

[0017]

Therefore, according to the present invention,
An ink jet recording apparatus, which has a liquid passage provided with an ejection heater and a common liquid chamber communicating with the liquid passage, uses a recording head for ejecting ink, and ejects ink onto a recording medium to perform recording. A heater provided in the common liquid chamber, a heater driving unit that drives the heater to heat ink in the common liquid chamber to generate ink convection, and drive by the heater driving unit to control the heater. Temperature control means for controlling the temperature of the ink in the liquid passage of the recording head and the common liquid chamber.

Further, a recording head for ejecting ink, which has a liquid passage provided with an ejection heater and a common liquid chamber communicating with the liquid passage, is used to eject ink onto a recording medium for recording. In an ink jet recording apparatus to perform, a heater provided in the common liquid chamber, a heater driving unit that drives the heater to heat ink in the common liquid chamber to generate ink convection, and a drive by the heater driving unit. Control means for controlling the temperature of the ink in the liquid passage of the recording head and the common liquid chamber, and controlling the position of the ink meniscus in the liquid passage.

[0019]

According to the above construction, the convection of the ink is generated by driving the heater provided in the common liquid chamber, which promotes the uniformization of the ink temperature in the common liquid chamber and the liquid passage. At the same time, since the ink supplied from the common liquid chamber to the liquid passage along with the ink ejection is heated to some extent, the difference in ink temperature between the print start time and the print end time can be reduced in the entire recording head.

In addition to controlling the ink temperature, the behavior of the ink meniscus in the liquid passage can be controlled by the ink convection in the common liquid chamber.

[0021]

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

9 to 14 show an ink jet unit IJU, an ink jet head IJH, an ink tank IT, an ink jet cartridge IJC, and an ink jet recording apparatus main body I to which the present invention is applied or applied.
It is a figure for demonstrating each and each relation of JRA and carriage HC. The configuration of each part will be described below with reference to these drawings.

(I) General Description of Apparatus Main Body FIG. 9 shows an ink jet recording apparatus I applied to the present invention.
It is an example of a general view of JRA. In the figure, the lead screw 5005 rotates by the forward and reverse rotation of the drive motor 5013 being transmitted via the drive force transmission gears 5011 and 5009. A pin (not shown) provided on the carriage HC is engaged with the spiral groove 5004 of the lead screw 5005, whereby the carriage HC is moved to the arrow a, b.
It is reciprocated in the direction. An inkjet cartridge IJC is mounted on the carriage HC. Fifty
A paper pressing plate 02 presses the recording paper P against the platen roller 5000 over the moving range of the carriage HC. Reference numerals 5007 and 5008 denote photocouplers, which are home position detecting means for confirming the presence of the lever 5006 of the carriage HC 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 ink with the inside of the cap as negative pressure. The suction ink is guided to the outside of the cap through an opening 5023 in the cap. Get burned. 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, the blade 5017 is not limited to this form and a known cleaning blade can be applied to this example. Reference numeral 5024 denotes a temperature or humidity sensor, which can detect the temperature and humidity of the ink jet recording apparatus and also predict the temperature of the recording head. This sensor may be attached to the inkjet cartridge IJC.

FIG. 17 shows the cleaning blade 5 described above.
It is a schematic diagram which shows one structure of the cleaner for cleaning 017.

With this configuration, the cleaning blade 5
By absorbing or scraping dust and ink droplets attached to 017, it is possible to prevent dust and the like from reattaching from the blade 5017 to the inkjet head IJH.
Specifically, as shown in FIG. 17, an ink absorber 7000 provided on the carriage HC absorbs ink droplets attached to the cleaning blade 5017 as the carriage HC moves. Although the absorber 7000 is provided on the carriage in this drawing, it may be fixed on the ink jet cartridge IJC to be dedicated so that it can be exchanged together with the IJC.

Referring again to FIG. 9, reference numeral 5021 denotes a lever for starting suction for suction recovery, which moves in accordance with the movement of the cam 5020 engaged with the movement of the carriage HC, and is driven by the drive motor. It controls the switching of the clutch that transmits the driving force.

The capping, cleaning, and suction recovery processes described above are performed by the lead screw 500 when the carriage HC moves to the home position side area.
By the shape of the spiral groove 5 and the rotation control of the motor 5013, desired processing can be performed at the corresponding positions. However, any configuration can be used as long as it can perform each predetermined operation at a desired timing.

Inkjet cartridge IJC of this example
As is clear from FIG. 11, the ink storage ratio is relatively large, and the tip of the ink jet unit IJU is slightly projected from the front surface of the ink tank IT. This inkjet cartridge IJC is an inkjet recording apparatus main body IJRA.
The carriage HC is detachably provided by a positioning mechanism and electric contacts described later.
It is a replaceable type.

(Ii) Description of Configuration of Inkjet Unit IJU The inkjet unit IJU is of a type that discharges using an electrothermal conversion element that generates thermal energy for causing film boiling to the ink in response to an electrical signal. It is a unit.

In FIG. 10, reference numeral 100 denotes electrothermal conversion elements (discharge heaters) arranged in a plurality of rows on the Si substrate,
It is a heater board formed by a film forming technique and electric wiring such as Al for supplying electric power thereto. Reference numeral 200 denotes a wiring board for the heater board 100, and a wiring corresponding to the wiring of the heater board 100 (for example, connected by wire bonding) and a pad located at an end of this wiring for receiving an electric signal from the main body device. It has 201 etc.

Reference numeral 1300 denotes a grooved top plate provided with a partition wall and a common liquid chamber for partitioning a plurality of ink flow paths, and an ink receiving port for receiving the ink supplied from the ink tank and introducing it into the common liquid chamber. 1500 is integrally molded with an orifice plate 400 having a plurality of discharge ports. Polysulfone is preferable as the integral molding material, but other molding resin materials can also be used.

Reference numeral 300 is a support plate made of, for example, a metal that supports the back surface of the wiring board 200 on a plane, and serves as a constituent member of the ink jet unit. Reference numeral 500 denotes a presser spring, which has an M-shape, presses the top plate 1300 at the center of the M-shape, and presses the portion corresponding to the liquid passage of the top plate 1300 with the linear pressure by the front salient part 501. Heater board 100 and top plate 1
In 300, the foot portion of the presser spring is the hole 3121 of the support 300.
By engaging with the back surface side of the support body 300 through these, they are fixed to each other by the biasing force of the pressing spring 500 and its front slant portion 501 in a state where they are sandwiched. Also,
The support 300 includes two positioning protrusions 1012 of the ink tank IT and a positioning and heat fusion holding protrusion 180.
Positioning holes 312, 190 that engage with 0, 1801
Besides having 0, 2000, it has projections 2500, 2600 for positioning the apparatus main body IJRA with respect to the carriage HC on the back surface side. In addition, the support 300 is an ink supply pipe 2200 that enables ink supply from the ink tank.
It also has a hole 320 that allows penetration (described below). The wiring board 200 is attached to the support 300 with an adhesive or the like.

Recesses 2400, 2400 of support 300
Are provided in the vicinity of the positioning projections 2500 and 2600, respectively, and in the assembled ink jet cartridge IJC (FIG. 11), the head tip region formed by a plurality of parallel grooves 3000 and 3001 on the three sides is formed. At the extension point, unnecessary objects such as dust and ink are projected 2.
It is located so as not to reach 500, 2600. The lid member 800 in which the parallel groove 3000 is formed is
As is clear from FIG. 11, the outer wall of the ink jet cartridge IJC is formed and the space portion for accommodating the ink jet unit IJU is formed. Further, the ink supply member 600 in which the parallel groove 3001 is formed.
Has an ink conduit 1600 continuous to the above-mentioned ink supply pipe 2200 as a fixed cantilever on the supply pipe 2200 side, and in order to secure a capillary phenomenon between the fixed side of the ink conduit 1600 and the ink supply pipe 2200. The sealing pin 602 is inserted. 601 is a packing for connecting and sealing the ink tank IT and the supply pipe 2200, and 700 is a filter provided at the tank side end of the supply pipe.

Since the ink supply member 600 is molded, the ink supply member 600 can be manufactured inexpensively and accurately, and the conduit 16 is formed in a cantilever shape so that the ink receiving port 15 of the conduit 1600 can be produced even in mass production.
The pressure contact state with respect to 00 can be stabilized. In this example, a complete communication state can be reliably obtained by pouring the sealing adhesive from the ink supply member side under this pressure contact state. To fix the ink supply member 600 to the support 300, the back surface side pin (not shown) of the ink supply member 600 with respect to the holes 1901 and 1902 of the support 300 is projected through the holes 1901 and 1902 of the support 300. This can be easily performed by heat-sealing the portion of the support 300 that protrudes to the back surface side. The slightly protruding area of the heat-sealed back surface is accommodated in the recess (not shown) in the side wall surface of the ink jet unit IJU mounting surface of the ink tank IT, so that the positioning surface of the unit IJU can be accurately obtained.

(Iii) Description of Configuration of Ink Tank IT As shown in FIG. 10, the ink tank includes a cartridge body 1000, an ink absorber 900, and an ink absorber 90.
0 is inserted from the side surface of the cartridge main body 1000 opposite to the above-mentioned unit IJU mounting surface, and a lid member 1100 for sealing the same. Reference numeral 900 denotes an absorber for impregnating ink, and the cartridge body 10
It is arranged in 00. 1200 is each of the above parts 100 to 60
0 is a supply port for supplying ink to the unit IJU, and the absorber 90 is formed by injecting ink from the supply port 1200 in the process before mounting the unit on the portion 1010 of the cartridge body 1000.
It is also an injection port for performing ink impregnation of 0.

In this example, the ink supply portion is the atmosphere communication port and this supply port, but in order to perform good ink supply from the ink absorber, the rib 2 inside the main body 1000 is used.
300 and partial ribs 2500 and 2400 of the lid member 1100
The in-tank air existing region formed by the above is formed continuously from the atmosphere communication port 1401 side and is formed over the corner area farthest from the ink supply port 1200. For this reason, the relatively good and uniform ink supply to the absorber is performed from the supply port 1200 side. This method is extremely effective in practice. The rib 1000 has four ribs parallel to the carriage movement direction on the rear surface of the ink tank body 1000 to prevent the absorber from adhering to the rear surface. In addition, the partial ribs 2400 and 2500 are similar to the rib 100.
It is provided on the inner surface of the lid member 1100 which is an extension corresponding to 0, but unlike the rib 1000, it is in a divided state and the air existence space is increased more than the former. The partial ribs 2500 and 2400 are the lid members 1.
It is distributed over less than half of the total area of 000. With these ribs, the ink in the corner area farthest from the tank supply port 1200 of the ink absorber can be more stably guided with a capillary force to the supply port 1200 side reliably. Reference numeral 1401 denotes an atmosphere communication port provided in the lid member for communicating the inside of the cartridge with the atmosphere. A liquid repellent material 1400 is disposed inside the atmosphere communication port 1401, and thus ink leakage from the atmosphere communication port 1401 is prevented.

Since the ink storage space of the above-mentioned ink tank IT has a rectangular shape and has long sides on its side surfaces, the rib arrangement configuration described above is particularly effective, but the long sides are arranged in the carriage movement direction. In the case of holding it or in the case of a cube, it is possible to stabilize the ink supply from the ink absorber 900 by providing ribs on the entire lid member 1100.

The structure of the mounting surface of the unit IJU of the ink tank IT is shown in FIG.

Let L ₁ be a straight line that passes through the center of the discharge port mounting surface of the orifice plate 400 and is parallel to the mounting reference surface of the bottom surface of the tank IT or the surface of the carriage.
Two locating ridges 1012 that engage holes 312 in support 300 are on this straight line L ₁ . The height of the protrusion 1012 is slightly lower than the thickness of the support 300, and
00 is positioned. On the extension of the straight line O1 in this drawing, 90 ° of the carriage positioning hook 4001 is located.
The claw 2100 with which the angular engagement surface 4002 engages is positioned, and the force for positioning the carriage is the straight line L.
It is configured to operate in a plane area parallel to the reference plane including ₁ . As will be described later with reference to FIG. 13, these relationships are
The positioning accuracy of only the ink tank is equivalent to the positioning accuracy of the ejection port of the head, which is an effective configuration.

Further, the protrusions 1800 and 1801 of the ink tank corresponding to the fixing holes 1900 and 2000 on the side face of the ink tank of the support 300 are the protrusions 10 described above.
It is for fixing the support 300 to the side surface by heat-sealing a portion which is longer than 12 and penetrates the support 300 and protrudes.

When the straight line passing through the protrusion 1800 is L ₃ and the straight line passing through the protrusion 1801 is L ₂ and is perpendicular to the straight line L ₁ , the center of the supply port 1200 is located on the straight line L ₃ . This is a preferable configuration because it acts to stabilize the connection state between the supply port 1200 and the supply pipe 2200, and the load on these connection states can be reduced even when dropped or impacted. Further, the straight lines L ₂ and L ₃ do not coincide with each other, and since the projections 1800 and 1801 are present around the projection 1012 on the ejection port side of the head IJH, the effect of reinforcing the positioning of the head IJH with respect to the tank is further enhanced. Is causing. The curve indicated by L ₄ is the outer wall position when the ink supply member 600 is mounted. Protrusion 180
Since 0 and 1801 are along the curve L ₄ , sufficient strength and positional accuracy are given to the weight of the configuration of the head IJH on the distal end side. 2700 is an ink tank IT
It is a brim at the tip of the carriage and is provided in the case of an abnormal case in which the displacement of the ink tank is extremely deteriorated by being inserted into the hole of the front plate 4000 of the carriage. Reference numeral 2101 is an engaging portion for engaging with a further positioning portion with the carriage HC.

The ink tank IT has a shape that surrounds the unit IJU except the lower opening by covering the unit IJU with the lid 800 after the unit IJU is mounted. However, since the ink jet cartridge IJC is mounted on the carriage HC. Since the lower opening of is close to the carriage HC,
A substantial four-way enclosed space is formed. Therefore, although the heat generated from the head IJH in the enclosed space is effective as a heat retaining space in this space, the temperature rises slightly for long-term continuous use. For this reason, in this example, a slit 1700 having a width smaller than this space is provided on the upper surface of the cartridge IJC in order to help the support body to radiate heat naturally, and the temperature distribution of the entire unit IJU is made uniform while preventing temperature rise. To be environment-independent.

When assembled as an ink jet cartridge IJC, the ink is supplied from the inside of the cartridge into the supply tank 600 through the supply port 1200, the hole 320 provided in the support 300, and the introduction port provided on the back side of the supply tank 600. After passing through the inside thereof, an appropriate supply pipe from the outlet and the ink inlet 150 of the top plate 400 are introduced.
Through 0 into the common liquid chamber. A packing made of, for example, silicone rubber or butyl rubber is provided in the above-mentioned connecting portion for ink communication, whereby sealing is performed and an ink supply path is secured.

In this embodiment, the top plate 1300 is made of a resin such as polysulfone, polyether sulfone, polyphenylenoxide, polypropylene, etc., which has excellent ink resistance, and is integrated with the orifice plate 400 in the mold. Simultaneous molding.

As described above, since the integrally molded part is the ink supply member 600, the top plate / orifice plate integrated, and the ink tank main body 1000, not only the assembly accuracy becomes high, but it is also extremely effective for improving the quality of mass production. Is. Further, since the number of parts can be reduced as compared with the conventional one, excellent desired characteristics can be surely exhibited.

(Iv) Description of Attachment of Inkjet Cartridge IJC to Carriage HC In FIG. 13, reference numeral 5000 denotes a platen roller, which conveys a recording medium P such as recording paper from below to above. The carriage HC moves along the platen roller 3000, and includes a front plate 4000 (thickness: 2 mm) located on the front platen side of the carriage, the front plate 4000 (thickness: 2 mm), and the cartridge IJ.
Pad 2 corresponding to pad 201 of wiring board 200 of C
Support sheet 4003 for electric connection portion holding a flexible sheet 4005 provided with 011 and a rubber pad 4006 that generates elastic force that presses the flexible sheet 4005 against each pad 2011 from the back surface side, and inkjet cartridge I
A positioning hook 4001 for fixing the JC at a predetermined mounting position is provided. The front plate 4000 has two positioning protrusion surfaces 4010 corresponding to the above-mentioned positioning protrusions 2500 and 2500 of the cartridge supporting resistance 300, respectively.
Receives a vertical force toward 10. For this reason, a reinforcing rib (not shown) is provided on the platen roller side of the acquisition plate 4000.
A plurality is formed extending in the direction of the vertical force. This rib also forms a head protection protrusion that protrudes slightly (about 0.1 mm) toward the platen roller from the front position L ₅ when the cartridge IJC is mounted. The support plate 4003 for electrical connection portions has a plurality of reinforcing ribs 4004 in the vertical direction, not in the direction of the ribs, and the ratio of lateral projection from the platen side toward the hook 4001 side is reduced. This also serves to incline the position when the cartridge is mounted as shown in the figure. Further, in order to stabilize the electrical contact state of the support plate 4003, the positioning surface 4008 on the platen side and the positioning surface 4 on the hook side are provided.
007, a pad contact area is formed between them, and a rubber sheet 4 with a botch corresponding to the pad 2011 is formed.
The deformation amount of 006 is uniquely defined. These positioning surfaces come into contact with the surface of the wiring board 300 when the cartridge IJC is fixed at a recordable position. In this example, since the pads 201 of the wiring board 300 are distributed symmetrically with respect to the straight line L ₁ described above, the deformation amounts of the respective bottches of the rubber sheet 4006 are made uniform and the contact pressures of the pads 2011 and 201 are increased. Is more stable. The distribution of the pads 201 in this example is two rows above and two rows below and vertically.

The hook 4001 has an elongated hole that engages with the fixed shaft 4009, and the platen roller 500 is rotated after rotating counterclockwise from the position shown in the drawing using the movement space of the elongated hole.
The inkjet cartridge IJC is positioned with respect to the carriage HC by moving to the left along 0. The hook 4001 may be moved by any structure, but a lever or the like is preferable. In any case, when the hook 4001 rotates, the cartridge IJC moves to the platen roller side, and the positioning protrusions 2500 and 2600 move the positioning surface 4010 of the front plate.
The hook surface 4002 at 90 ° by moving the hook 4001 to the left side.
While closely contacting the 90 ° surface of the JC claw 2100, the cartridge IJC is swung in the horizontal plane about the contact area between the positioning surfaces 2500 and 4010 and finally the pads 201 and 20.
Contact between 11 people begins.

When the hook 4001 is held at a predetermined position, that is, a fixed position, the pads 201 and 2011 are in full contact with each other, the positioning surfaces 2500 and 4010 are in full contact with each other, and the 90-degree surface 4002 and the claw 90 are in contact with each other. Contact between the two surfaces, the wiring board 300 and the positioning surfaces 4007, 4
The surface contact with 008 is simultaneously formed, and the holding of the cartridge IJC with respect to the carriage is completed.

(V) Description of Heater Board FIG. 14 is a schematic view of the heater board 100 of the head used in this embodiment.

A temperature adjusting heater (sub-heater) 8d for controlling the temperature of the recording head, an ejection portion array 8g provided with an ejection heater (main heater) 8c for ejecting ink, a liquid chamber sub-heater 8i, a drive element. 8h are formed on the same substrate in the positional relationship shown in FIG.
By arranging each element on the same substrate in this way, the head temperature can be detected and controlled efficiently, and the recording head can be made compact and the manufacturing process can be simplified.

Further, in the figure, the position of the cross section 8f of the outer peripheral wall of the top plate, which is divided into an area where the heater board is filled with ink and an area where the heater board is not filled, is shown with respect to the heater board 100. The discharge heater 8c side of the outer peripheral wall section 8f of the top plate functions as a common liquid chamber 82 (hereinafter, also simply referred to as a liquid chamber). The outer peripheral wall of the top plate is also formed on the ejection portion array 8g (not shown), and the groove portions formed therein form a plurality of liquid passages 81 corresponding to the ejection ports.

(Vi) Description of Control Configuration Next, a control configuration for executing recording control of each unit of the above-described apparatus configuration will be described with reference to the block diagram shown in FIG.

In the figure showing the control circuit, 10 is an interface for inputting a recording signal from a host device, 11 is an MPU, 12 is a program ROM for storing a control program executed by the MPU 11, and 13 is various data ( It is a dynamic RAM that stores the above-mentioned recording signals and recording data supplied to the head), and can also store the number of recording dots, the number of times the recording head is replaced, and the like.
A gate array 14 controls the supply of print data to the print head 18 (IJH), and also controls the transfer of data between the interface 10, the MPU 11, and the RAM 13. Reference numeral 5013 is a carrier motor shown in FIG. 9, and 19 is a carry motor for carrying the recording paper. Reference numeral 15 is a head driver for driving the ejection of the recording head, and 16 and 17 are motor drivers for driving the carry motor 19 and the carrier motor 5013, respectively.

FIG. 16 is a circuit diagram showing the details of each part of FIG.

The gate array 14 includes the data latch 14
1, a SGMENT (SEG) shift register 142, a multiplexer (MPX) 143, a common (COM) timing generation circuit 144, and a decoder 145. The recording head 18 has a diode matrix structure, and discharge heaters (H1 to H64) where the common signal COM and the segment signal SEG match according to the recording data. In the following description, the recording head has 128 discharge ports. Since there are 128 discharge heaters,
Only 64 are shown here for the sake of simplicity. ), A drive current flows, and the ink is heated and ejected.

The decoder 145 decodes the timing generated by the common timing generation circuit 144 and selects any one of the common signals COM1 to COM8. The data latch 141 latches the recording data read from the RAM 13 in 8-bit units, and the multiplexer 143 outputs the recording data as segment signals SEG1 to SEG8 according to the segment shift register 142. The output from the multiplexer 143 can be variously changed according to the contents of the shift register 142, such as 1 bit unit, 2 bit unit, or all 8 bits as described later.

The operation of the above control structure will be described. When a recording signal is input to the interface 10, the gate array 14 is activated.
And the MPU 11 convert the recording signal into recording data for printing. Then, the motor drivers 16 and 17 are driven, and the recording head is driven according to the recording data sent to the head driver 15 to perform recording.

The apparatus described above has the recording head drive control means described below.

(1) Target Temperature Setting Means In the print head drive control for stabilizing the ejection amount described below, the temperature of the print head substrate (hereinafter, also simply referred to as head temperature) is used as a control reference. That is, the head temperature is used as a substitute characteristic for detecting the ejection amount per ink droplet ejected at that time. However, even if the head substrate temperature is constant, the ink temperature in the ink tank depends on the environmental temperature, so the ejection amount may differ. For the purpose of eliminating this difference, the target temperature is a value that defines the head temperature at which the ejection amount becomes equal for each environmental temperature (that is, for each ink temperature of the tank). The target temperature is preset as a target temperature table. The target temperature table used in this embodiment is shown in FIG.

(2) Recording Head Temperature Calculation Unit The recording head temperature is estimated and calculated from past input energy. The calculating means is a discrete value stacking calculating means which treats the temperature change of the recording head discretely as a stack of temperature changes per a predetermined time, and the discrete change of the head temperature within the range of energy that can be input. 2 has a two-dimensional table means which is calculated in advance and is made into a table, which is a two-dimensional matrix according to the input energy per a predetermined time and the elapsed time.

The reason why the head substrate temperature is not detected by using the sensor but is calculated and estimated from the input energy is that the response is better when calculated and estimated than when the sensor is used.

Arrow head It is possible to promptly cope with changes in substrate temperature and cost can be reduced. The calculated and estimated head temperature serves as a reference for ejection drive and sub-heater drive in this embodiment.

In this embodiment, as the heat source for raising the temperature of the recording head, two heaters, that is, a discharge heater for printing and a sub-heater for the common liquid chamber are used.

Since the recording head is composed of a plurality of members, it is general that the members have different heat capacities and different thermal time constants. Therefore, in the temperature estimation of the print head in the present embodiment, the heat source is two, that is, the discharge heater and the common liquid chamber sub-heater, and the members that take the heat capacity into consideration are the head substrate (and its vicinity) and the base plate (and the vicinity). It is represented by the following two, and the estimation is performed approximately.

From the above, in order to estimate the change (Δt) in the head temperature, the temperature is estimated in four modes as shown below, and the temperature rise (Δt) in the head temperature is obtained by adding all four temperatures. .

Change in temperature of head substrate by discharge heater (ΔTmh) The predetermined time for estimating rise and fall of temperature is “50 msec”,
If the input energy per unit time is represented by "duty", the following table shows the temperature change for each predetermined time when the heater is driven at each duty. Here, the influence of each heater drive is "0.8 sec"
Shall remain.

[0067]

[Table 1]

Temperature change of base plate by discharge heater (ΔTmb) The unit time for estimating rise and fall of temperature is “1 sec”. Further, when the influence of the heater driving remains for “512 sec”, ΔTmb can be obtained from the same table as above.

The temperature change (ΔTsh) of the head substrate by the sub heater is assumed to be “50 msec” as a unit time for estimating temperature rise and temperature drop. Further, when the influence of the heater drive remains for “0.8 sec”, ΔTsh is calculated from the table similar to the above.
Can be obtained.

Temperature change of the base plate due to the sub-heater (ΔTsb) The unit time for estimating rise and fall of temperature is “1 sec”. Further, when the influence of the heater driving remains for “512 sec”, ΔTsb can be obtained from the same table as above.

Based on the temperature changes obtained above,
The temperature change of the recording head at this moment is

[0072]

[Expression 1] Δt = ΔTmh + ΔTmb + ΔTsh + ΔTsb

(3) PWM (Pulse Width Modulation) Control If the recording head is driven at the head substrate temperature described in the target temperature table under each environment, the ejection amount can be stabilized. However, the head substrate temperature varies depending on the print duty and the like and is not constant. Therefore, in order to stabilize the ejection amount, the recording head is driven by the PWM drive using a plurality of pulses, and the ejection amount is controlled without depending on the head temperature. In the present embodiment, the ejection drive condition is determined by presetting a PWM table that defines drive pulses having different waveforms / widths at that time depending on the difference between the head temperature and the target temperature under the environment. FIG. 19 shows the PWM table used in this embodiment.

However, the unit of the values in the table is the state (1 state =
0.181 μsec), and the weighting factors are (t ₀ , t ₁
= 1 and p ₁ and p ₂ = 1/16).

That is, t ₀ and t ₁ are [table values]
× 0.181 μsec p ₁ and p ₂ are [table values] × 0.181 / 16 μs
ec Further, when the head is driven, the pulse width is corrected by the head rank. The correction value for each rank is as shown in FIG.

The correction value is multiplied by all [t ₀ , t ₁ , p ₀ , p ₁ ].

Note that [cal] in the table is a weighting coefficient when the head temperature is calculated when the head is driven with the corresponding PWM value. For example, [cal = 83%] means that when the number of heat dots per unit time is 10,000, it is corrected to 8300 dots by multiplying by a correction value of 83%. That is, it is a coefficient for converting the number of heat dots into an energization ratio to which electric power is applied.

Specific examples of the present invention will be described below using the apparatus having the head driving means described in (1) to (3) above.

(Embodiment 1) In the present embodiment, the sub heater (liquid chamber sub heater) provided in the common liquid chamber is used for temperature control and meniscus vibration control, and the ink in the recording head is efficiently and uniformly distributed within a constant temperature region. It is intended to always perform normal ejection and to record a high-quality image by controlling the state of ink and the meniscus state of the ink in the liquid path during ejection.

An optimum drive control method for the liquid chamber sub-heater for realizing high quality recording will be described below.

The temperature changes in the liquid passage and in the common liquid chamber due to the heating of the sub-heater in the common liquid chamber tend to be as shown in FIG. When the heating of the sub-heater is started, the ink temperature in the common liquid chamber gradually rises, and the temperature in the liquid passage gradually rises as compared with that in the common liquid chamber. The sub-heater in the liquid chamber is in direct contact with the ink in the liquid chamber, and the heat from this heater is absorbed by the ink in the vicinity of the heater, causing convection of the ink in the common liquid chamber and in the common liquid chamber and the liquid passage in a short time. The ink can be heated uniformly to the desired temperature.

When the heating of the sub-heater in the liquid chamber is stopped and the printing is started, the ink temperature is lowered immediately after that, but it is considerably gentler than the temperature drop gradient of the sub-heater outside the liquid chamber or the heater for ejection described in the conventional example. Become. In addition, the ink temperature in the liquid path immediately before the end of printing does not become so low as immediately after the start of printing. This is because the ink in the common liquid chamber, which is supplied into the liquid passage along with printing, is heated to some extent. Therefore, there are the following advantages in controlling the ink temperature by the sub-heater in the liquid chamber.

High heating efficiency Low responsiveness to heating Uniform heating can be used for other purposes (meniscus control described later) The liquid chamber sub-heater can obtain a desired discharge amount even when the above PWM drive is performed. When not present, it can be effectively used for controlling the head temperature to approach the target temperature by driving immediately before printing. Depending on the difference between the head temperature and the target temperature under that environment, a different liquid chamber sub-heater driving time at that time is preset, and the driving condition of the liquid chamber sub-heater is determined. The driving time of the sub heater is set from the sub heater table according to the difference (Δt) between the target temperature and the actual head temperature. In this example, there are two types of sub-heater tables, that is, "rapid acceleration sub-heater table" and "normal sub-heater table", and they are used properly according to the conditions described below.

[When Resuming Printing from the Pause of Printing] As shown in FIG. 21, when 10 seconds or more has elapsed from the last printing end point, the "rapid acceleration sub-heater table" is used. If it is less than 10 seconds, the "normal sub heater table" is used.

[During continuous printing] Further, as shown in FIG.
The "normal sub-heater table" is used after 5 seconds or more have elapsed since printing was resumed from the print pause state. If it is less than 5 seconds, the table used at the start of printing is inherited. That is, when the rapid acceleration sub-heater table is used, the "rapid acceleration sub-heater table" is used, and when the normal sub-heater table is used, the "normal sub-heater table" is used.

The purpose of using the two tables properly is to prevent a decrease in throughput. That is, since the discharge amount control by the sub-heater in the liquid chamber is a method of controlling the discharge amount by raising the head temperature, it takes a relatively long time to raise the temperature, so that the desired temperature rise is completed within the ramp-up time of the carriage. If not, it is necessary to delay the start of printing and spend time for raising the temperature, which has the adverse effect of reducing the throughput. Therefore, the above 2
FIG. 20 shows a specific drive table for the sub-heater in the liquid chamber, which uses two tables.

Meniscus control using the liquid chamber sub-heater will be described below.

In order to perform normal ink ejection, the ink in the liquid path must be in a normal meniscus state when bubbling by the ejection heater. However, the actual ink in the print head is subjected to pressure due to foaming and defoaming by the ejection heater, negative pressure of the ink absorber in the ink tank, and force due to the capillary force of the liquid path. Therefore, the meniscus repeats the movement in the discharge direction and the opposite direction with the discharge in the liquid path. This movement (vibration) cycle of ink is governed by the printing pattern, and when the vibration cycle is synchronized with the natural frequency of the ink supply system (including the ink tank, common liquid chamber, liquid passage, and ejection port), it is normal. The meniscus may vibrate to such an extent that proper ejection cannot be performed.

Therefore, by performing drive control using the liquid chamber sub-heater as a pressure generation source, drive control is always performed so as to forcibly create an optimum meniscus state during ink ejection.

The configuration of the drive condition setting register of the liquid chamber sub-heater for vibration control in this embodiment will be described.

<Driving condition setting register> a. Register for setting drive order of sub-heater in liquid chamber (4 types / 2 bits) b. Setting register for the minimum number of heat dots in the column that starts this control (max129 / 8 bit) c. Delay setting register for driving sub heater of common liquid chamber (max 200 μs / 8 bit) d. Common liquid chamber sub-heater drive initial number setting register (12
8 times / 8 bit) e. Pulse width setting register (Pre5bit / off6
(bit / main6 bit / off8 bit) Conditions are set in advance in the registers a to e, and the liquid chamber sub-heater is driven by the routine shown in FIG.

Next, the flow of the entire control system will be described with reference to FIGS. 1, 2 and 3.

FIG. 2 shows an interrupt routine for setting a PWM drive value for ejection and a liquid chamber sub-heater drive condition.

This interrupt routine is generated every 50 msec. Therefore, the PWM value and the liquid chamber sub-heater driving condition are constantly updated every 50 msec, regardless of whether printing is in progress or at rest, or whether the sub-heater needs to be driven or not.

First, when a 50 msec interrupt is applied, the print duty for the last 50 msec is referred to (S2010). However, the print duty referred to at this time is a value obtained by multiplying the number of dots actually ejected by the weighting coefficient for each PWM value, as described in the PWM control section. From the duty of 50 msec and the printing history of 0.8 seconds in the past, the heat source is the discharge heater and the temperature rise temperature (ΔT
mh) is calculated (S2020).

Similarly, the drive duty of the sub-heater in the liquid chamber for 50 msec is referred to (S2030).
Based on the sub-heater drive duty for 50 msec and the sub-heater drive history for the past 0.8 seconds, the temperature rise temperature (Tsh) of the member group whose heat constant is the sub-heater and whose time constant is the short range is calculated (S2040). Then, the temperature rise temperature (ΔTm) of the member group whose heat source is the discharge heater and whose time constant is long range, which is calculated in the main routine described later.
b) and the temperature rise (ΔTsb) of the member group whose heat source is the liquid chamber sub-heater and whose time constant is long range, and by adding them together (= ΔTmh + ΔTsh +
ΔTmb + ΔTsb) Head temperature is calculated (S205)
0).

Next, the target temperature is set in the target temperature table (see FIG. 1).
8)) (S2060), and the temperature difference (ΔT) between the head temperature and the target temperature is obtained (S2070). From this temperature difference ΔT, the PWM table, and the liquid chamber sub-heater table, P which is the optimum head drive condition according to ΔT
The WM value, liquid chamber sub-heater drive table selection, and drive time are set (S2080 to S2090).

Then, the driving conditions a to e for driving the sub heater in the liquid chamber by vibration control are set (S210).
0).

FIG. 3 shows a temperature calculation routine near the base plate.

First, the print duty for the past 1 second is referred to (S3010). However, the print duty referred to at this time is a value obtained by multiplying the number of dots actually ejected by the weighting coefficient for each PWM value, as described in the PWM control section. Duty of this 1 second and past 5
From the printing history for 12 seconds, the heat source is the discharge heater, the temperature rise temperature (ΔTmb) of the member group with a long time constant is calculated, and the data is stored and updated in a memory location that can be easily referenced when interrupted after 50 msec. Yes (S302
0). Next, similarly, the drive duty of the sub-heater for 1 second is referred to (S3030). From the drive duty of the sub-heater for 1 second and the drive history of the sub-heater for the past 512 seconds, the heat source is the sub-heater and the time constant is a long range member group. The temperature rise temperature (ΔTsb) is calculated. ΔTm
Similar to the case of storing and updating b, the memory is stored and updated in a memory location determined so that it can be easily referred to at the time of interruption after 50 msec (S3040).

Then, printing and driving of the liquid chamber sub-heater (temperature control, vibration control) are performed in accordance with the PWM value which is updated each time an interrupt is received every 50 msec and the liquid chamber sub-heater driving condition.

FIG. 1 shows the main routine.

When the print command is sent (S1010), it is selected whether the normal table or the rapid heat table is cited (S1020). Subsequently, the liquid chamber sub-heater is driven according to the conditions set in the liquid chamber sub-heater drive condition setting routine (S1030). In order to use the sub-heater in the liquid chamber as a vibration control heater, the actual number of heat dots (M) is detected for each column (S104).
0). It is determined whether the actual number of heat dots is larger than the set value b (S1050), and when the condition is satisfied, the process for driving the sub-heater in the liquid chamber is started.

That is, first, the drive delay time d <0 is discriminated, and it is determined whether the drive is performed before the one-column printing or after the one-column printing (S1060). If d <0, the liquid chamber sub-heater is driven according to the set conditions, and then one-column printing is performed according to the PWM value (S1090).
~ S1110). When d ≧ 0, 1 according to the PWM value
After performing column printing, the sub-heater in the liquid chamber is driven (S1070 to S1080). When one line is printed, S
Return to 1010. In other cases, the driving of the liquid chamber sub-heater is stopped (S1120), and the process returns to S1040.

In this embodiment, double-pulse and single-pulse PWM is used to control the ejection amount and the head temperature, but triple-pulse or more-pulse PWM may be used.

Further, when the head substrate temperature is higher than the print target temperature and the head substrate temperature cannot be lowered even if the head substrate temperature is lowered by PWM with small energy, the carriage scanning speed may be controlled. Alternatively, the scanning start timing of the carriage may be controlled.

The constants such as the cycle of temperature prediction (50 msec interval and 1 sec interval) used in this embodiment are examples and do not restrict the present invention.

By controlling the recording head as described above, the sub-heater in the liquid chamber can be used as a temperature control means for stabilizing the ejection amount and a vibration control means for optimizing the meniscus state at the time of ejection. It is possible to record high-quality images in density unevenness and shobo using an inkjet recording device.

(Embodiment 2) In this embodiment, a driving method for more efficiently controlling the temperature by the sub-heater in the liquid chamber will be described.

In the first embodiment described above, the ink in the recording head is heated by driving the sub-heater in the liquid chamber for a short pulse. This is to prevent foaming by the sub-heater in the liquid chamber that is in contact with the ink. In this embodiment, by combining the sub-heater of the liquid chamber with a short pulse drive and a drive used for a normal ejection heater in which bubbling and defoaming occur, convection of ink occurs in the common liquid chamber, and the ink is more evenly and more uniformly. The ink in the recording head is brought to a desired temperature in a short time, the time required for raising the temperature is shortened, the throughput of the recording apparatus is prevented from lowering, and the ejection amount is stabilized.

A print head temperature calculation routine, P
The routine for setting the WM value and the sub-heater driving time in the liquid chamber is the same as in the first embodiment.

ON / OFF of short pulse (1 μsec) is set to 1
Every time it is repeated 00 times (200 μsec), the foaming pulse (5 μsec) is turned on and off 10 times. By driving the sub-heater in the liquid chamber as described above, the following effects can be obtained.

FIG. 5 is a schematic diagram showing convection of ink in the liquid chamber when the above-described driving method of this embodiment is used.

In the driving method of this example, first, as shown in FIG. 5A, thermal diffusion to ink is performed by short pulse driving,
Next, as shown in FIG. 5B, foaming and defoaming by foaming are performed to promote ink convection, and thermal diffusion from the liquid chamber sub-heater to ink during the next short pulse drive (FIG. 5).
(C)) is promoted. As a result, the amount of heat transferred from the sub-heater in the liquid chamber to the ink in the recording head becomes larger than that in the heating by only the short pulse drive.

By performing the driving as described above, it becomes possible to control the ink in the common liquid chamber and the liquid passage more uniformly and at a desired temperature in a short time.

(Third Embodiment) In the first and second embodiments, the liquid chamber sub-heater is driven for vibration control during printing, but here, the liquid chamber sub heater is controlled for both vibration control and temperature control. A control method of using and selectively driving the wrinkles will be described.

In the first embodiment, the driving condition of the liquid chamber sub-heater during printing is determined by how many dots are printed in one column. Therefore, when the prescribed number of dots is not reached, the liquid chamber sub-heater is driven with a short pulse.
The driving time is 160 μsec for one column printing time (6 kHz, 128 ejection ports, 8 blocks).

The print head temperature calculation routine, the PWM value, and the set value of the liquid chamber sub-heater drive time during non-printing are the same as those in the first embodiment. However, in the temperature calculation routine, a process of adding the energy input by the sub-heater in the liquid chamber during the printing of one column is added.

By performing the drive control described above, the energy applied to the recording head increases, the high temperature gradient of the ink during printing becomes gentle as shown in FIG. 6, and the sub-heater for driving the liquid chamber is driven during non-printing. Time is reduced. Therefore, density unevenness during printing is further reduced and throughput is improved.

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

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

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

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 a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

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

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

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

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

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

[0129]

As is clear from the above description, according to the present invention, the convection of the ink is generated by driving the heater provided in the common liquid chamber, whereby the common liquid chamber and the liquid passage are formed. Uniformization of the ink temperature is promoted. At the same time, since the ink supplied from the common liquid chamber to the liquid passage along with the ink ejection is heated to some extent, the difference in ink temperature between the print start time and the print end time can be reduced in the entire recording head.

Further, the behavior of the ink meniscus in the liquid passage can be controlled by controlling the ink temperature and by the ink convection in the common liquid chamber.

As a result, it is possible to provide an ink jet recording apparatus capable of recording ink with a constant ink temperature in the liquid path and performing high-quality image recording without uneven density.

[0132]

[Brief description of drawings]

FIG. 1 is a flowchart showing a procedure of print head temperature control according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure for setting drive conditions for a liquid chamber sub-heater used in the above control.

FIG. 3 is a flowchart showing a procedure of base plate temperature calculation processing according to the above control.

FIG. 4 is a diagram showing a temperature change in a print head by a sub-heater in a liquid chamber according to an embodiment of the present invention.

5A to 5C are schematic diagrams for explaining driving of a liquid chamber sub-heater according to another embodiment of the present invention.

FIG. 6 is a diagram showing a temperature change in the recording head when the sub-heater in the liquid chamber is driven during printing according to another embodiment of the present invention.

FIG. 7 is a diagram showing a change in temperature inside the print head due to driving of a sub-heater outside the liquid chamber in the conventional print head.

FIG. 8 is a diagram similar to FIG. 7 showing a change in temperature inside the print head due to driving of an ejection heater in the conventional example.

FIG. 9 is a schematic perspective view of an inkjet recording apparatus to which the present invention is applied.

FIG. 10 is an exploded perspective view of the inkjet cartridge shown in FIG.

FIG. 11 is an external perspective view of the inkjet cartridge.

FIG. 12 is a perspective view for explaining a head unit mounting portion of the inkjet cartridge.

FIG. 13 is an explanatory diagram for explaining mounting of the inkjet cartridge on a carriage.

FIG. 14 is a schematic diagram for explaining a heater board that constitutes the recording head of the cartridge.

FIG. 15 is a block diagram showing a control configuration of the recording apparatus.

16 is a block diagram showing details of the control configuration shown in FIG.

FIG. 17 is a schematic diagram showing a configuration of a cleaning unit in the recording apparatus.

FIG. 18 is a schematic diagram showing a target temperature table according to an embodiment of the present invention.

FIG. 19 is a schematic diagram showing a drive pulse setting table according to an embodiment of the present invention.

FIG. 20 is a schematic diagram showing a liquid chamber sub-heater drive table and drive pulses according to an embodiment of the present invention.

FIG. 21 is an explanatory diagram for explaining the proper use of the liquid chamber sub-heater drive table.

[Explanation of symbols]

 8c Ejection heater 8i Liquid chamber heater 11 MPU 12 ROM 13 RAM 14 Gate array 18 (IJH) recording head

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location B41J 3/04 103 X (72) Inventor, Mr. Iwasaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Kiya Non-Incorporated (72) Inventor Atsushi Arai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kiichiro Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (2)

[Claims] 1. A recording head for ejecting ink, comprising a liquid passage provided with an ejection heater and a common liquid chamber communicating with the liquid passage, and ejecting the ink onto a recording medium for recording. In an ink jet recording apparatus for performing, a heater provided in the common liquid chamber, a heater driving unit that drives the heater to heat ink in the common liquid chamber to generate ink convection, and a drive by the heater driving unit. An ink jet recording apparatus comprising: a temperature control unit that controls the temperature of the ink in the liquid path of the recording head and the common liquid chamber by controlling the temperature of the ink. 2. A recording head for ejecting ink, comprising a liquid passage provided with an ejection heater and a common liquid chamber communicating with the liquid passage, and ejecting the ink onto a recording medium for recording. In an ink jet recording apparatus to perform, a heater provided in the common liquid chamber, a heater driving unit that drives the heater to heat ink in the common liquid chamber to generate ink convection, and a drive by the heater driving unit. To control the temperature of the ink in the liquid passage of the recording head and the common liquid chamber and to control the position of the ink meniscus in the liquid passage. apparatus.