JPH05220947A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To record a required image, character, or the like by preventing the deterioration of ink refilling characteristics which occurs when high-speed recording is performed under a low-temperature environment. CONSTITUTION:If an environmental temperature is low (step S116), an initial action is conducted (step S102) within a period from the completion of one-page recording to the start of next-page recording to ensure the time for positively supplying ink to delivery ports.

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 an ink jet recording apparatus capable of stably maintaining ink ejection performance.

[0002]

2. Description of the Related Art Conventionally, a recording apparatus for recording on a recording medium such as paper or OHP sheet (hereinafter referred to as recording paper or simply paper) has been proposed in the form of mounting recording heads of various recording systems. ing. This recording head has
There are a wire dot method, a thermal method, a thermal transfer method, and an inkjet method. In particular, the ink jet method, which directly ejects ink onto a recording sheet, is attracting attention as a quiet recording method with low running cost. Among the inkjet methods, the thermal energy recording method using film boiling has been put into practical use as an excellent one in terms of high speed, high density, etc., as compared with the method using a piezoelectric element.

[0003]

The ink jet recording head has a driving frequency within a predetermined range when given a predetermined driving condition, and recording can be carried out within this range without any problem. Further, although the recording head satisfies a predetermined response characteristic, it may be necessary to perform recording by exceeding the characteristic. In addition, there was a case where the characteristics of the recording head, which should be stable, were partially affected and the recording characteristics were partially deteriorated.

The deterioration of the image due to the deterioration of the recording characteristics of the recording head has the following phenomena. Droplet landing position on the recording medium shifts vertically "horizontal twisting", horizontal landing position shifts "horizontal twisting", and further droplets desired for image formation do not form multiple small liquids. This is the case when the droplets are divided into droplets and discharged in a mist state, or in the worst case, almost no droplets are discharged. The above-mentioned various phenomena of deterioration may occur independently at the initial stage of deterioration, but in many cases, all of the various phenomena are observed as the deterioration progresses.
As a result, the formed image may be significantly deteriorated as compared with the desired image.

The above-mentioned deterioration of the recording characteristics is often recognized when the recording environment temperature is low and ink is continuously ejected by a sheet supplying device or the like which automatically supplies a recording medium into the recording device. It was In particular, a shorter time interval for each recorded page is likely to occur earlier than a longer condition.

As a construction of the recording head, a sponge or the like is used as an ink holding member in order to prevent the ink in the ink tank from leaking to the outside by integrating the ink tank and the head portion, and to absorb the sponge (negative pressure). On the contrary, there is a configuration in which ink is supplied to the ejected droplet forming portion by a capillary phenomenon and is detachably attached to the apparatus and replaceable. In many cases, in the case of the replaceable recording head, the above-described deterioration of the recording characteristics occurs earlier in a state where the remaining amount of ink is reduced to some extent than in a state where the remaining amount is not reduced. The deterioration of the recording characteristics is likely to occur earlier in a state where the remaining ink amount in the recording head is low than in a state where the remaining ink amount is large.

Further, in addition to these conditions that are likely to occur, when the ejection frequency of the liquid droplets is the same, it is also a feature that the amount of ink ejected within a certain fixed time is more likely to occur.
Specifically, the following phenomena are mentioned.

In an ink jet recording apparatus, the viscosity of the ink increases and the ejection amount of the ink decreases in a low temperature environment, so that the dot diameter obtained on the recording medium decreases,
Image deterioration occurs such that a gap easily occurs between adjacent dots. In order to solve this phenomenon, another heater (maintaining heater, sub-heater) is provided in the vicinity of the discharge heater (main heater) that is involved in bubble formation for discharging droplets, and discharges at low temperature by energizing this heater. The temperature control (temperature control) such as heating the vicinity of the heater is performed to increase the ink ejection amount. When the temperature control was carried out, the various phenomena described above often occurred from an early stage because the ink ejection amount increased as compared with the case where the temperature control was not carried out. In addition, there is a feature that the higher the target temperature when heating is, the easier it is to occur earlier than when the target temperature is low.

Further, in the serial type printer in which the replaceable head is mounted on a carrier configured to be slidable along a guide shaft and droplets are ejected as the carrier moves to form a desired image. Are the following phenomena. When bidirectional recording is performed in which droplets are ejected in both directions in which the carrier can be moved, and when the recording time required per page of the recording medium is significantly shortened, the same droplet ejection frequency as the bidirectional recording is used. Even if there is, the amount of ejected ink is increased as compared with the one-way recording state, and therefore it has been recognized that the various phenomena described above occur remarkably early.

The main cause of these problems is that the re-ink supply (refill) performance to the nozzles after the ink droplets are discharged changes depending on the operating environment temperature, more specifically, the temperature of the ink itself, particularly the temperature of the ink in the ink tank. There is a thing. That is, when the use environment temperature is low, the viscosity of the ink itself increases and the refill performance deteriorates. In addition, this refill performance may also change depending on the remaining ink amount when a holding member such as a sponge is used in an ink tank-integrated head to prevent the ink in the ink tank from leaking to the outside. is there. That is, the holding power of the sponge (negative pressure) due to the decrease in the amount of ink remaining
This is because the refill performance deteriorates due to the increase in Due to these causes, a situation occurs in which the head does not follow the ejection frequency used, which leads to the various phenomena of deterioration.

More specifically, when ink is supplied from the ink tank to the respective nozzles via the common liquid chamber, the ink supply characteristics from the ink tank to the common liquid chamber deteriorate and the nozzles It is considered that the refilling performance for the

In the above replaceable head, the influence of ink suction pressure and holding force of sponge, etc. is eliminated.
It is possible to reduce these suction pressure and holding force,
It is not practical because it easily causes ink leakage from the ink tank.

The present invention is intended to solve the above-mentioned problems of the prior art, and prevents deterioration of recording characteristics that occur in various usage states of a recording head or a recording apparatus equipped with the recording head. An object of the present invention is to provide an inkjet recording device capable of recording desired images, characters, and the like.

[0014]

In order to solve the above-mentioned problems, the ink jet recording apparatus of the present invention is designed so that the ink droplet ejection characteristics of the recording head change depending on desired recording conditions and recording conditions. A feature of the present invention is that the supply of ink to the liquid passage or the ejection portion is optimized by changing the driving method of the recording medium conveyance that is unrelated to the driving of the recording head.

According to the present invention, the desired image can be printed because the printing can be performed always under stable conditions without being affected by the change in the ink droplet ejection characteristics of the printing head and because the driving of the printing head is not changed. It can be stably obtained. In addition, since ink droplets to be recorded can be recorded without thinning, it is possible to obtain an image that is visually comparable to practical use.

[0016]

EXAMPLES Examples of an ink jet recording apparatus of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of the configuration of a printer section of the ink jet recording apparatus according to this embodiment. Here, 1 is a head cartridge having an inkjet recording head,
Reference numeral 2 is a carriage for mounting this and scanning in the X direction in the drawing. 3 is a head cartridge 1 and a carriage 2
Hooks 4 for attaching to the hooks and 4 are levers for operating the hooks 3. Reference numeral 5 is a support plate that supports an electrical connection portion for the head cartridge 1. Reference numeral 6 is an FPC (flexible printed circuit) for connecting the electrical connection part and the main body control part. Reference numeral 7 is a guide shaft for guiding the carriage 2 in the S direction, and is inserted into a bearing 8 of the carriage 2. 9 has the carriage 2 mounted, and this is X
Is a timing belt for transmitting power for moving in the direction, and pulleys 10 arranged on both sides of the device.
It is stretched over A and 10B. The driving force is transmitted from the carriage motor 11 to one pulley 10B via a transmission mechanism such as a gear. Reference numeral 12 denotes a conveyance roller that regulates the recording surface of a recording medium such as paper and conveys the recording medium at the time of recording, and is driven by a conveyance motor 13. Reference numeral 14 is a paper pan for guiding the recording medium to the recording position, and 15 is a pinch roller which is disposed in the feeding path of the recording medium and presses the recording medium toward the conveying roller 12 to convey the same. .. Reference numeral 16 denotes a platen that faces the ejection port of the head cartridge 1 and regulates the recording surface of the recording medium. A paper discharge roller 17 is arranged downstream of the recording position in the recording medium conveyance direction and discharges the recording medium toward a paper discharge port (not shown). A spur 18 is provided corresponding to the paper discharge roller 17, and presses the paper discharge roller 17 via a recording medium.
The conveyance force of the recording medium by the discharge roller 17 is generated. Reference numeral 19 is a release lever for releasing the bias of the pinch roller 15 and the spur 18 when setting the recording medium.

Both ends of the platen 16 are rotatably supported by the shafts of the paper discharge rollers 17, and are biased from the stop position of the left and right plates 20 toward the entire surface portion 21 of the paper pan 14 to make the transport roller 12 smaller than the outermost circumference. Part 12A
12A provided at a plurality of positions are in contact with the inside of the entire surface portion 21 of the paper pan.

Reference numeral 22 denotes a cap made of an elastic material such as rubber which faces the ink ejection port forming surface of the recording head at the home position, and is supported so as to be able to come into contact with and separate from the recording head. The cap 22 is used for protection of the recording head during non-recording, and for ejection recovery processing of the recording head.

In the ejection recovery process, the cap 22 is opposed to the ejection port forming surface and an energy generating element provided in the ink ejection port and used for ejecting the ink is driven to eject the ink from all the ejection ports. Processing for removing ejection failure factors such as air bubbles and dust, or ink that has increased in viscosity and is no longer suitable for recording (preliminary ejection)
Alternatively, this is a process of removing the cause of ejection failure by forcibly ejecting the ink from the ejection port with the ejection port forming surface covered with the cap 22.

The cap 23 acts as a suction force for forcibly discharging the ink, and at the time of the discharge recovery process by the forcible discharge or the discharge recovery process by the preliminary discharge, the cap 22.
It is a pump used for sucking the ink received in the ink. Reference numeral 24 is a waste ink tank for storing the waste ink sucked by the pump 23. The waste ink tank 24 is connected to the pump 23 by 28 tubes.

Reference numeral 25 denotes a blade for wiping the ejection port forming surface of the recording head. The blade 25 is located at a position where it projects toward the recording head side and performs wiping during the carriage movement and a retracted position where it does not engage with the ejection port forming surface. It is movably supported. 26 is a motor, 27 is a power transmission from the motor 26, and drives the pump 23 and the cap 2
This is a cam device for moving the blade 2 and the blade 25 respectively.

T is a temperature sensor provided to detect the temperature (environmental temperature) in the recording apparatus. The temperature sensor T is a well-known thermistor showing an output voltage according to a temperature change, and an output signal is input to an MPU 1000 described later through a predetermined signal amplification circuit or the like.

FIG. 2 schematically shows the construction of a replaceable ink cartridge head in which the ink tank and the head portion are integrated. 29 is a nozzle part, and there are 64 nozzle parts. Reference numeral 30 denotes a common liquid chamber for temporarily storing ink to be supplied to each nozzle. Reference numeral 31 is a chip tank, which is a pipe connecting the ink tank portion and the common liquid chamber 30. Reference numeral 32 denotes a sponge in the ink tank, which holds the ink so that the ink does not leak due to the generated negative pressure. Reference numeral 33 is a filter that prevents air bubbles, dust, and the like from entering the chip tank. When the thermal energy generating element (not shown) is energized, the ink filled in the nozzle is 29
The nozzle is configured to discharge the ink. Although not shown, the above-mentioned sub heater is used for the common liquid chamber 3
There are two locations within 0.

Next, the sheet feeding device 39 mounted in the printer section shown in FIG. 1 will be specifically described with reference to FIG.

(Load Separation Means) The load separation means comprises a guide means 40 and a separation means 41, and the recording medium (sheets) S set between the guide means 40 have their leading ends aligned by the separation means 41. In addition to being stacked, the sheets are separated one by one by the feeding means 42 and the separating means 41 at the time of feeding. The separating means 41 has separating claws 41a urged by springs (not shown) on both sides below the guide means 40. When the recording medium S is fed by the feeding means 42, a plurality of stacked sheets are loaded. The recording medium S can be separated when only one of the recording media passes over the separation claw 41a.

(Pressing Means) The pressing means 43 is for pressing the recording medium S against the feeding roller 42a, and the pressing means has a pressing plate 43a rotatably attached to the frame 44, and Pressing plate 43a and frame 44
There is a spring 45 between them, and this spring causes the pressing plate 43 to
Is urged toward the feeding roller 42a. Therefore,
The loaded recording media S are pressed by the pressing plate 43a, and the uppermost recording medium comes into pressure contact with the feeding roller 42a.

(Feeding Means) Next, the feeding means 42 is for giving a feeding force to the set recording medium S, and in the present embodiment, is constituted by a feeding roller 42a which is driven and rotated. There is. The feeding roller 42a is, as shown in FIG. 4, a shaft 42 rotatably attached to a frame 44.
A drive transmission means 46 is connected to the shaft 42b, and is connected to the shaft 42b via the drive transmission means 46 and the conveyance motor 13 which is the conveyance drive means of the recording apparatus.

(Clutch) Next, a clutch for transmitting / disconnecting power from the transport motor 13 (FIG. 1) to the feeding roller 42 will be described. Shaft 4 of feeding roller 42a
As shown in FIGS. 4 and 5, a paper feed gear 46a, a clutch 46b, a clutch gear 46c, etc., which constitute the drive transmission means 46, are disposed on one end side of the 2b. The paper feed gear 46a is concentrically and integrally fixed to the shaft 42b, the clutch 46b is a cylindrical member concentrically and rotatably supported by the shaft 42b, and the clutch gear 46c is also concentrically and rotatably supported by the shaft 46b. There is. The clutch 46b is the paper feed gear 4
It is located concentrically on the outside of 6a.

Clutch 46b of the clutch gear 46c
A clutch pawl 46d is swingably provided on the side surface on the side, and when the clutch gear 46c rotates, the clutch pawl 4d is rotated.
The tip of 6d has a degree of freedom that allows it to slide on the outer periphery of the cylindrical clutch 46b to the clutch 46b side to some extent in the axial direction of the support shaft.

FIG. 4 shows the clutch-on state, in which the tip of the clutch pawl 46d is recessed in the notch hole 46e formed in the outer periphery of the clutch 46b and engages with the paper feed gear 46a. ing. In this state, the forward rotation force of the carry motor 13 is transmitted through the relay gear train G (only the last one is shown in the figure) to the clutch gear 46.
When it is transmitted to c, the rotation of the clutch gear 46c is transmitted to the sheet feeding gear 46a, and the sheet feeding roller 42 rotates in the recording medium feeding direction indicated by the arrow. On the other hand, FIG.
The clutch-off state is shown in which the clutch pawl 46d is disengaged from the paper feed gear 46a by the reverse driving of No. 3.

FIG. 6 (A) is a development view of the peripheral surface of the clutch 46b on which the clutch pawl 46d slides, and FIGS. 6 (B) and 6 (C) are lines BB and CC in FIG. 6 (A), respectively. FIG. In this drawing, stoppers for HP1 and HP2 are provided on the peripheral surface of the clutch 46b, and S1 indicates the cutout hole 46e. There is a step boundary line between La and Lb at the boundary between the region SHP1 on the HP1 side and the region SHP2 on the HP2 side. When the clutch pawl 46d moves from HP1 to HP2, it moves from HP1 → Lb → HP2 and from HP2. H
When moving to P1, HP2 → La → HP1 is moved. Clutch claw 46d moves from HP2 to HP1
The direction in which the feeding roller 42 moves forward is the direction in which the recording medium is normally fed, and the direction in which the feeding roller 42 moves from HP1 to HP2 is the direction in which it is reversely fed.

4 to 6, even if the clutch claw 46d is located at an arbitrary position, the clutch 46b is cut out to form the cutout hole S1.
The initializing operation is performed so that the clutch pawl 46d can be securely inserted into the HP1. The distance from HP1 to S1 is constant (for four lines of printing in this example), and if the clutch claw 46d is located on HP1, it is easy to surely move it to S1. In the initialization operation, when the clutch pawl 46d is in the area surrounded by S1 and S1 and Ld, when the clutch pawl 46d is moved in the HP1 direction, the clutch pawl 46d is inserted into S1 and the clutch-
Since it will be in an ON state, in order to avoid this, the clutch claw 10d is initially moved to HP2 for implementation. Since the clutch pawl 10d surely moves from SHP2 to HP1, the initialization operation can be all performed by moving the clutch pawl 46d to the HP2 side and then moving to HP1. By thus rotating the carry motor 13 forward and backward, it becomes possible to switch the drive transmission to the feeding roller 42.

FIG. 7 is a block diagram showing an example of the configuration of the control system of the printing apparatus having the configuration described so far. In the figure, reference numeral 1000 denotes an MPU for controlling each unit by executing a control procedure such as a preset program.
Reference numeral 01 is a ROM which stores programs and the like corresponding to the control means, and 1002 is a RAM used as a work area when executing the control procedure. Reference numeral 1003 denotes a timer that measures time such as control execution.
Is an interface unit for connecting to each unit of the printer. Reference numeral 38 is a keyboard for performing various key inputs.

The cap position and the movement position of the carriage 2 can be detected by the recovery system home sensor 35 and the carriage home sensor 36. 1a, 11
Reference numerals a, 13a, and 26a are drivers for driving the head 1, the carriage motor 11, the carry motor 13, and the recovery system motor 26, respectively. Further, 34 is a temperature sensor for measuring the ink temperature, and T is a temperature sensor for measuring the environmental temperature of the recording apparatus.

Next, a method of driving the ejection energy generating element of the recording head will be described. FIG. 8 is a diagram showing the energization timing of the discharge energy generating element (hereinafter referred to as a heater). The heaters of 64 nozzles are not energized at the same time in order to keep the maximum current low, and are energized every 8 times in 8 steps. The 64 nozzles are divided into 8 blocks of a to h, and each is performed for 7 μs in order from a, with 8 μs not being energized. For example, when the printing speed is 64 characters / second, the ejection frequency is 3072 Hz, and if one character consists of 48 dots, then 48 dots × 64 characters / second, so the heat interval A of a dot during continuous ejection is approximately 326 μm.
Seconds or 1/3072 Hz. When performing continuous ejection, the refill performed after ejection is, for example, 326 μm.
Must be completed within a drive period of seconds.

Next, with reference to FIG. 9, a recording processing procedure in the above-described recording apparatus and sheet feeding apparatus will be described. First, when the power of the recording apparatus is turned on, the recovery system motor 26 is operated to set the recovery system unit to the recovery system home position, the cap 22 is retracted, and then the carriage 2 is set to the home position. After that, the cap 22 is brought into contact with the nozzle portion of the recording head again to be in a waiting state for receiving a recording signal.

When a recording command is input (S101), the above-mentioned clutch pawl 46d whose initial position is unknown is moved to HP1 (FIG. 6), so that the transport motor 13 is rotated for 10 reverse rotations, and further for 10 forward rotations. Rotate (S102). next,
The conveyance motor 13 is rotated in the opposite direction for four rows to move the clutch pawl 46d from HP1 to the hole S1 (46e) to bring the clutch-on state (FIG. 4) (S103). After that, the feeding roller 42 is rotated by driving the conveying motor in the normal direction, and the recording medium is fed to the recording apparatus (S104). The leading end of the recording medium is the transport roller 13
When the position between the pinch roller 15a and the pinch roller 15a is exceeded, the conveyance motor is reversely driven for three lines to move the clutch pawl 46d from the hole S1 to the region SHP2 and put in the clutch-off state (FIG. 5) (S105). Further, the carry motor 13 is driven in the normal direction to carry the print medium until it faces the position where the print head prints on the print medium (S106, S10).
7).

Next, after the cap 22 is retracted and removed from the nozzle portion of the recording head (S108), the carriage 2 is set at the home position and a predetermined preliminary ejection is performed (S109) to start a desired recording. The carriage is moved to the position (S110). Then, the recording head is driven based on the received recording data to record on the recording medium (S111, S112). When the recording of one page is completed,
The conveyance motor 13 is driven in the normal direction to convey the recorded recording medium from the inside of the recording apparatus to the sheet feeding apparatus (S11).
3). Further, it is judged whether or not the next page is continuously recorded (S114), and in the case of continuous recording, the ambient temperature sensor T provided in the recording apparatus detects the ambient temperature (S116), and the temperature is 19 ° C or higher. In case of, go to S103, 19 ℃
In the following cases, the process returns to S102.

Here, in normal continuous recording, if the initial operation of the clutch of the sheet feeding device (S102) is performed only when the first page is fed, the clutch claw 46d is at a predetermined position from page 2 onward. Therefore, there is no need for initial operation. However, when the temperature of the ink, especially the ink temperature in the ink tank is a low temperature of 19 ° C. or lower, the deterioration of the recorded image occurs due to the deterioration of the refilling performance described above.

Therefore, in this embodiment, the initial operation of the clutch is performed on page 2 and after so that the refill is normally performed during the time during which the initial operation is performed.
Then, the above operation is repeated and the recording of the last page is completed, whereby a series of recording operations is completed (S115). In this way, by switching the operation of the sheet supply device depending on the ink temperature, continuous recording can be performed without lowering the refill performance after ink ejection. The ink temperature may be detected by the ink temperature sensor 34 provided in the recording head.

(Embodiment 2) In Embodiment 1, the temperature inside the recording apparatus is detected as a criterion for determining whether to perform the initial operation of the clutch of the sheet feeding apparatus even after the second page during continuous recording. It was carried out, but this Example 2
Is determined by using the remaining amount of ink in the ink tank as the criterion. It should be noted that the temperature inside the recording apparatus or both the ink temperature and the remaining amount may be detected.

FIG. 10 is an explanatory diagram of a recording head in which the ink remaining amount detecting means 37 is provided in the chip tank 31.
The ink detection means 37 is a pressure sensor or the like and outputs a pressure that changes according to the remaining amount of ink in the ink tank, and outputs the pressure through the interface unit 1004 of FIG.
00 is input.

In this embodiment, when a recording command is input and recording is executed, in S116 shown in FIG. 9 described above, for example, when the remaining ink amount is 1/2 or less, S102 is performed.
If it is 1/2 or more, it is determined to proceed to S103.
In this way, by adopting a configuration in which an appropriate drive method can be selected according to the change in the ink remaining amount, it is possible to select the drive method according to the deterioration of the refill performance of the recording head caused by the decrease in the ink remaining amount. It is possible to prevent deterioration. Although the pressure sensor is used as the ink remaining amount detecting means, a means for detecting the weight of the ink or the weight of the recording head may be used, and an electric resistance detecting means is further provided in the ink tank to detect the detected current. Alternatively, the remaining ink amount may be calculated from the voltage or the resistance value.

Further, as shown in FIG. 11, a recording dot number detecting means 1005 for detecting the number of recording dots may be provided and used. In this case, the replaceable head is provided with means for detecting whether or not the head is attached to the recording apparatus, and cumulatively counts the total number of recording dots from the unused state to detect the remaining ink amount. You may. Further, in the permanent type in which only the ink tank is replaced, the total number of recorded dots after the replacement of the ink tank may be counted.

(Third Embodiment) In the third embodiment, as the means for selecting the driving method of the sheet feeding device, the number of liquid droplets recorded in a predetermined partitioned area, that is, the recording duty.
May be used.

As described above, the recording dot number detecting means 1005 shown in FIG. 11 is a means for counting the number of recording dots from the recording data to be recorded. In the dot matrix system, one character is usually divided into blocks of 48 × 48 dots to form a character or an image. FIG. 12 shows an example of the character “A”, which is 48 × 48.
Since the character “A” is formed by using 464 dots out of 2304 dots, the recording duty is 464 /
2304 × 100 = 20%. Normal Japanese sentences have a mixture of kanji and hiragana and the average recording duty of one character is about 20 to 25%. Therefore, the total average recording duty can be calculated by counting the total number of recording dots in one page by the means 1005 for detecting the number of recording dots and dividing by the total number of recording characters. Also, the number of recording dots may be divided by the number of possible recording dots of one page, and in this case, it is not necessary to count the number of recording characters. However, since there are space dots between normal characters, it is necessary to use the calculated total average recording duty in consideration of the space dots.

The calculated recording duty is the MPU of FIG.
1000 is input to the MPU 1000, and the MPU 1000 shown in FIG.
In S116 shown in FIG.
When ty is 30% or more, it is determined to proceed to S102, and when it is less than 30%, it is determined to proceed to S103. In this case, the driving method of the sheet feeding device is switched when the recording duty is slightly higher than the normal sentence. Thus record d
By adopting a configuration in which the driving method can be selected according to the change of the duty, the optimum driving method can be selected according to the deterioration of the refill performance of the recording head due to the high recording duty,
It is possible to prevent the deterioration of the image due to the deterioration of the refill performance.

Further, the driving method of the sheet feeding device may be determined by detecting and calculating all of the above-mentioned device internal temperature, ink remaining amount, and recording duty.

(Fourth Embodiment) In the first embodiment, the driving method of the sheet feeding device is classified into the case where the initial operation of the clutch is performed after page 2 and the case where the initial operation is not performed.
The fourth embodiment provides a so-called weight for holding the motor in a stopped state when switching the rotation direction when the transport motor is rotated in the normal direction or the reverse direction in order to feed the recording medium from the sheet supply device. is there.

FIG. 13 shows a control flow in the case where the sheet feeding device is made to wait during the operation according to the temperature inside the device and the recording duty.

In FIG. 13, steps S101 to S115 are the same as the flowchart shown in FIG. In this case, when continuous recording is performed, the temperature inside the apparatus is detected in S216, and the total average recording duty of the previously recorded one page is calculated (S217). Then, the wait time of the sheet feeding device is determined from the detected in-apparatus temperature and the total average recording duty from the wait time table shown in FIG. 14 (S21).
8) Wait for the determined time (S219).
After that, the process proceeds to S103, and the feeding operation is continued.

FIG. 14 shows the wait time table described above. The lower the temperature inside the device, the more du
The higher the ty, the lower the refill performance, so 5 ℃
In the following, when the average recording duty is 81% or more, the longest waiting time is set to 8 seconds. When the temperature inside the apparatus is 26 ° C. or higher, the wait time is 0 second, that is, the wait is not performed regardless of the recording duty.

In FIG. 13, the case where the recording medium is automatically fed to the recording device by using the sheet feeding device has been described, but the case where the recording medium is manually set without using the sheet feeding device is described. Also has the same effect. In this case, the time from the end of recording on the previous page until the recording medium on the next page is set and the recording command is received is counted, and if the time in the wait time table in FIG. 14 is not reached, It is sufficient to wait until the table time comes.

Further, the same effect can be obtained by providing the weight during the transportation within the page instead of the time interval between pages. In this case, by using a wait time table (not shown) for waiting while the recording medium is conveyed to the next line, the wait time is determined from the internal temperature of the apparatus and the previously recorded one-line recording duty. Just go.

(Fifth Embodiment) In the fifth embodiment, the time required for refilling is ensured by changing the drive frequency of the conveying motor when the recording medium is fed from the sheet feeding device. FIG. 15 shows a control flow in the case of changing the driving frequency of the carry motor during the operation of the sheet feeding apparatus according to the temperature inside the apparatus and the recording duty.

In FIG. 15, the driving frequency of the conveying motor during recording is set to 1000 pps (pulse / sec), and the driving frequency during operation when the recording medium is fed from the sheet feeding device into the recording device is changed. The case is shown. In this case, when the first sheet is fed (S302 to S30
In 6), all are driven at 1000 pps, and for the second and subsequent sheets, first the internal temperature of the apparatus is detected in S317, and then the total recording duty of one page is calculated (S318). Then, the drive frequency of the carry motor is determined from the table (not shown) from the internal temperature of the apparatus and the recording duty (S319), and the drive frequency is set to A (S320). Then proceed to S303,
Continue feeding operation.

In FIG. 15, only the driving frequency during the operation of the sheet feeding device is changed, but the same effect can be obtained by changing the driving frequency of the conveying motor during recording.
In this case, instead of the total print duty of one page, the print duty of one line recorded after the end of the print of one line may be calculated, and the transport time to the next line may be changed.

(Sixth Embodiment) In the first embodiment, the temperature inside the apparatus is detected and the driving method of the sheet feeding apparatus is switched, but in the sixth embodiment, refilling is performed by changing the recording direction. It secures the time required.

The refill performance of the recording head depends on the recording duty.
Recording du per unit time
ty, that is, whether printing with the same number of dots in a short time or over a long time is a problem. For example, in bidirectional recording and unidirectional recording, the refill performance is lower in bidirectional recording. This means that it takes t seconds for the carriage to move from left to right or right to left.
Considering the case of line recording, recording can be performed in 2t seconds when recording in both directions and 3t seconds when recording in one direction. Since the same two lines are printed, the total number of dots printed is the same, whereas the bidirectional printing is completed in 2/3 of the unidirectional printing. Therefore, the bidirectional recording has a higher recording duty per unit time than the unidirectional recording, and a faster refill performance is required.

Therefore, the recording duty is used to switch between bidirectional recording and unidirectional recording. For example, when the total average recording duty within one page is 30% or more during bidirectional recording, unidirectional recording is performed, and when it is less than 30%, bidirectional recording is switched. In this case, since the recording duty within the page must be counted before recording, for example, the recording duty of the previously recorded line is counted, and it is determined whether the next line is recorded in both directions or in one direction. May be. This allows
The refill performance can be maintained without changing the drive frequency during feeding from the sheet feeding device and during conveyance during recording.

(Embodiment 7) In each of the above embodiments, the time until the start of recording on the next line or the next page is changed according to the refill performance of the recording head, but the physicochemical characteristics of the ink itself involved in recording are different. In this case, the wait time, the transportation speed of the transportation means, the temperature that serves as a reference for changing the driving method, and the like are different. Therefore, in the seventh embodiment, when there are a plurality of types of recording heads that can be mounted on the recording apparatus, or when a plurality of recording heads are mounted, and inks having different physicochemical characteristics are used ( For example, for inks of different colors, etc., the time is set for each recording head corresponding to each ink.

Here, a case will be described in which the ink can be mounted on the recording apparatus and the color of the ink is different for each recording head and the characteristic relating to the refill characteristic of the ink is different. An example of means for detecting the ink color of the recording head is shown in FIG. FIG.
1 shows details of the electrical contact portion 56 of the head 1 mounted and driven in the recording apparatus of FIG.
Are electrically connected to the FPC 6 on the support plate 5 (FIG. 1). Specifically, the electrical contact 51 and an electrical contact (not shown) of the FPC 6 are joined together, and a detection signal is input to the MPU 1000 through the FPC 6.

16 (A), (B), (C), and (D) show the electrical joints of the head cartridge 1 corresponding to each color. For example, (A) shows black (Black), (B). )
Shows the case of red (Red), (C) shows the case of green (Green), and (D) shows the case of blue (Blue). In FIG. 16, 5
Reference numerals 2, 53, 54 and 55 are patterns for color detection, and are based on (A) as a basic form.
3, 54 are connected to + 5V through FPC6, and 55 is connected to GND.

Here, in (A), 52 to 55
Up to are electrically connected. In this case, the detected signals are 0, 0, 0, 0 (where 0 indicates the GND level) in order from 52, and therefore the ink color is black (B
The recording head of (black) is determined by the above detection signal. For the red (Red) recording head, the detection signals are 1, 0, 0, 0 (where 1 indicates + 5V level) in order from 52, and so on (C). ) Green is 1, 1, 0, 0, (D)
In blue, it is 1, 1, 1, 0.

In the structure in which the MPU 1000 can discriminate the type of the recording head mounted in the recording apparatus in this way, a driving method selection table is set for each recording head by a driving method suitable for each recording head and ink. can do. For example, when the viscosity of black ink is higher than that of other inks, when the temperature inside the device is used as the driving method determination means, even if the detected temperature is the same, the recording of the next line or the next page is not started. By increasing the time, and conversely, when the viscosity of the ink is low, by shortening the time, a driving method suitable for black ink can be set.

(Embodiment 8) The replaceable head in which the ink tank portion and the nozzle portion are integrated has been described so far, but a so-called permanent head in which the ink tank portion and the nozzle portion are separated is used. The present invention can be applied to the conventional inkjet recording apparatus. It can also be applied to a full line type recording head in which the recording device has a length corresponding to the maximum width of the recording medium. In this case, the conveyance speed of the recording medium is kept constant during recording by the recording head, and the same effect can be obtained by changing the conveyance speed or changing the wait time only when there is a space between the images to be recorded. Is obtained. Furthermore, although the inkjet method using thermal energy has been described, it can be applied to a piezo jet method in which electricity is converted into force to eject ink.

The present invention brings excellent effects particularly in a recording head and a recording apparatus of a system utilizing heat energy among the ink jet recording systems.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, a liquid (ink) is used.
By applying at least one drive signal that corresponds to the recorded information and gives a rapid temperature rise exceeding nucleate boiling, to the electrothermal converter arranged corresponding to the sheet or liquid path in which is held, This is effective because heat energy is generated in the electrothermal converter to cause film boiling on the heat acting surface of the recording head, and as a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, U.S. Pat. Nos. 4,463,359 and 43,
Those as described in 45262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned 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 459600 is also included in the present invention. In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective as a configuration based on JP-A-59-138461, which discloses a configuration that corresponds to the discharge portion.

[0071]

As described above, according to the present invention, the driving method which is not related to the driving of the recording head can be variably constituted and the ink can be optimally selected according to the change of the refill performance of the recording head. It is possible to stably maintain the ejection performance of, and it is possible to prevent image deterioration.

[Brief description of drawings]

FIG. 1 is a perspective view showing an inkjet recording apparatus equipped with a disposable head to which the present invention is applied.

FIG. 2 is a partial explanatory diagram of a disposable head.

FIG. 3 is a cross-sectional view showing an ink jet recording apparatus equipped with a sheet feeding apparatus to which the present invention is applied.

FIG. 4 is a perspective view showing a clutch-on state of a clutch unit of the sheet feeding device.

FIG. 5 is a perspective view showing a clutch-off state of a clutch unit of the sheet feeding device.

FIG. 6 is a cross-sectional view of a clutch portion of the sheet feeding device.

FIG. 7 is a block diagram showing a control unit of a recording apparatus to which the present invention is applied.

FIG. 8 is an explanatory diagram showing recording timing of a recording head.

FIG. 9 is a flowchart showing a recording procedure of the recording apparatus to which the present invention is applied.

FIG. 10 is a partial explanatory view of another recording head provided with the ink remaining amount detecting means according to the present invention.

FIG. 11 is a block diagram showing a control unit of another recording apparatus to which the present invention is applied.

FIG. 12 is an explanatory diagram of an image forming method by a dot matrix method.

FIG. 13 is a flowchart showing another recording procedure according to the present invention.

FIG. 14 is another drive method selection table according to the present invention.

FIG. 15 is a flowchart showing another recording procedure according to the present invention.

FIG. 16 is a partial description of a head having means for determining the type of head.

[Explanation of symbols]

 1 Head Cartridge 2 Carriage 29 Nozzle Section 30 Common Liquid Chamber 37 Ink Remaining Detecting Means 39 Sheet Supply Device 42a Feeding Roller 46b Clutch 46d Clutch Pawl 1000 MPU 1001 ROM 1002 RAM 1003 Timer 1005 Recording Dot Number Detecting Means T Temperature Sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B41J 11/42 A 9011-2C 19/76 9212-2C 9012-2C B41J 3/04 104 K (72 ) Inventor Tetsuya Ishikawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (13)

[Claims] 1. An ink jet recording apparatus for performing recording using a recording head for ejecting ink from a discharge port onto a recording medium, in order to secure the supply of ink to the discharge port, one line recording is completed according to the recording conditions. An ink jet recording apparatus, wherein the time from the start of recording to the next line is variable. 2. The ink jet recording apparatus according to claim 1, wherein a predetermined wait time is provided between the end of recording of one line and the start of recording of the next line according to recording conditions. 3. The ink jet recording apparatus according to claim 1, further comprising a conveying unit that conveys the recording medium, wherein a conveying speed at which the conveying unit conveys the recording medium is changed according to recording conditions. 4. The ink jet recording apparatus according to claim 1, wherein the recording direction of the recording head is switched to bidirectional recording or unidirectional recording according to recording conditions. 5. An ink jet recording apparatus for performing recording using a recording head for ejecting ink from a discharge port onto a recording medium, in order to secure the supply of ink to the discharge port, one page recording is completed according to recording conditions. An ink jet recording apparatus, characterized in that the time from the start of recording to the next page is changed. 6. The ink jet recording apparatus according to claim 5, wherein a predetermined wait time is provided between the end of recording of one page and the start of recording of the next page according to recording conditions. 7. A sheet feeding device for continuously feeding a recording medium, wherein a feeding speed of the recording medium fed from the sheet feeding device is changed according to a printing condition. The inkjet recording device described. 8. The ink jet recording apparatus according to claim 5, wherein a predetermined wait time is provided between the start of feeding of the sheet feeding device and the start of recording according to recording conditions. 9. A detecting means for detecting an environmental temperature, wherein the time until the start of recording of the next line or the next page is changed according to the environmental temperature detected by the detecting device. 9. The inkjet recording device according to any one of 1 to 8. 10. An ink tank configured to hold ink in an ink absorbing / holding member, and means for detecting the ink remaining amount in the ink tank, the next line or the next page depending on the ink remaining amount. The ink jet recording apparatus according to claim 1, wherein the time until the start of recording is changed. 11. A means for detecting the number of ink droplets recorded in a predetermined area, wherein the time until the start of recording on the next line or the next page is changed according to the number of ink droplets recorded. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is an inkjet recording apparatus. 12. The method according to claim 1, further comprising means for detecting the type of ink used for ejection, and changing the time until the start of recording of the next line or the next page according to the type of ink. 8
The inkjet recording device according to any one of 1. 13. The ink jet recording apparatus according to claim 1, wherein the recording head causes a state change in the ink by thermal energy and ejects the ink based on the state change. ..