JP2005161813A - Printing timing correcting method of inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an ink droplet hit always an ideal position by correcting a hitting position of the ink droplet in an inkjet printer. <P>SOLUTION: A discharge timing of an ink droplet is varied according to change of a head moving speed, a distance between a head and paper, and an ink droplet discharge speed. When an edge interval of time of an encoder signal is t1; an edge interval of time of an encoder signal at an expected maximum head scanning speed is t2; a period of time for the ink droplet discharged from the head to reach a recording medium is t3; a period of time required for the ink droplet to move a distance between the head and the paper, changed to an ideal distance between the head and the paper is t4; and a period of time to delay a printing timing is t, a following formula: A=t3/t2, t=(t1-t2)*A+t4 is satisfied. A function to variably adjust the A and t4 according to the change of the ink droplet discharge speed is also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus and an ink jet recording method for recording an image on a recording medium using a recording head capable of ejecting ink.

Inkjet recording devices are widely used as a means for recording images (including characters and symbols) on recording media such as paper and plastic thin plates (OHP, etc.) that are mounted on printers, fax machines, and copying machines based on image information. Has been.
FIG. 2 is a perspective view of a main part of the ink jet recording apparatus. In FIG. 2, a recording medium 201 is supported by a recording medium feeding roller 202 disposed in a recording area, a rib on a platen 212, and a spur 213, and the feeding roller 202 is driven by a sheet feeding motor 203. , And conveyed in the sub-scanning direction of arrow α. As the sheet feeding motor 203, a stepping motor or a DC motor is used. In recent years, DC motors are widely used for reasons such as quietness. In that case, a rotary encoder (not shown) is installed in the feed roller 202, and the sheet feed motor 203 is controlled based on an encoder signal obtained therefrom. A shaft 204 is provided in front of the feed roller 202 in parallel therewith. The carriage 205 is movably guided by the shaft 204 and is reciprocated in the main scanning direction indicated by an arrow β via the belt 207 by the output of the carriage motor 206. Lubricating oil such as grease is applied between the shaft 204 and the carriage 205 in order to reduce a mechanical load due to friction or the like.

  As the carriage motor 206, a stepping motor or a DC motor is used in the same manner as the sheet feeding motor 203. In recent years, DC motors are widely used for reasons such as quietness. In that case, a linear encoder (not shown) is arranged on the carriage 205 and a linear encoder scale (not shown) is arranged in parallel with the shaft 204. The carriage motor 206 is controlled based on a signal obtained from the linear encoder. Further, based on a signal obtained from the linear encoder, a timing for ejecting ink from the recording head 208 is also generated.

  A carriage 205 serving as a recording head moving unit is equipped with a recording head 208 and a tank 209 that stores recording ink. The recording head of this example is for a color image, and is arranged along the scanning direction of the carriage 205 so that the black ink ejection head 208-BK, the cyan ink ejection head 208-C, and the magenta ink ejection head. A head 208-Y for discharging 208-M and yellow ink is disposed. As the tank 209, a tank 209-BK for black ink (BK), a tank 209-C for cyan ink (C), a tank 209-M for magenta ink (M), and a tank for yellow ink (Y) 209-Y is mounted to supply ink to the head corresponding to each color. An ink discharge portion is provided on the front surface of the recording head 209, that is, the surface facing the recording surface of the recording medium 201 with a predetermined interval (for example, 0.8 mm). In the ink discharge portion, a plurality of (for example, 48 or 64) ink discharge ports are arranged in a vertical line along a direction intersecting the scanning direction of the carriage 205.

  In addition, a control unit including a control circuit (CPU, ASIC) of the recording apparatus (not shown) and a ROM, a RAM, etc. attached thereto, for example, the recording mode information and recording data from the controller of the external host device via the interface, for example. Receive. Then, the control unit of the recording apparatus controls the recording head 208 via the head driving circuit together with driving sources such as various motors in the recording apparatus based on these information and recording data. Ink is ejected from the ink ejection unit, and an image is recorded on the recording medium 201. That is, the operation of ejecting ink from the ink ejection unit while moving the recording head 208 in the main scanning direction and the operation of transporting the recording medium 201 by a predetermined amount in the sub-scanning direction are alternately repeated, thereby An image is recorded on the medium 201.

  FIG. 3 is an explanatory diagram of the relationship between the moving speed of the recording head 208 and the landing position of the ink droplet on the recording medium 201.

It is assumed that the recording head 301 is mounted on the carriage and moves at a head speed V305 in the main scanning direction β in the figure. In this case, when the ink droplet 302 is ejected from the recording head 301 toward the recording medium 303 at the ink ejection velocity Vd 306, the ink droplet 302 is a vector composition speed and direction of the head velocity V 305 and the ink ejection velocity Vd 306. Fly in. Then, the ink droplet 302 moves a distance d between the recording head 301 and the recording medium 303 and lands on a landing position 304 on the recording medium 303.
JP-A-7-101062 JP-A-8-90776

  However, the speed of the ink droplets ejected from the recording head may change due to various factors.

  FIG. 4 shows a change in the ink droplet landing position when the velocity of the ink droplet ejected from the recording head changes. When the distance between the recording head 401 and the recording medium 402 is d403, the moving speed (scanning speed) of the recording head 401 is V404, and the ejection speed of the ink droplet 405 is Vd406, the ink droplet 405 moves the recording head 401. It flies in the vector composition speed and direction of the speed (scanning speed) V404 and the ejection speed Vd406 of the ink droplet 405. As a result, it lands at a position 407 on the recording medium 402. On the other hand, when the ejection speed of the ink droplet 405 changes to Vd ′ 408, the ink droplet 405 moves in the vector composition speed and direction of the moving speed (scanning speed) V 404 of the recording head 401 and the ejection speed Vd ′ 408 of the ink droplet 405. To fly. As a result, it reaches a position 409 on the recording medium 402. That is, when the discharge speed of the ink droplet is slower, the flying angle with respect to the vertical line from the recording head 401 to the recording medium 402 becomes wider, and as a result, the ink lands at a position far from the recording head 401.

  In this way, when the speed of the ink droplets ejected from the recording head changes, the landing position of the ink droplets shifts and the recorded image is disturbed.

  An object of the present invention is to provide an ink jet recording apparatus and an ink jet recording method capable of recording a high-quality image without being affected by a change in the speed of ink droplets ejected from a recording head.

  The inkjet recording apparatus of the present invention uses a recording head capable of ejecting ink, and performs recording on the recording medium by ejecting ink from the recording head while relatively moving the recording head and the recording medium. In an inkjet recording apparatus, an encoder that outputs a pulse each time a relative amount of the recording head and the recording medium moves, a detection unit that detects an interval time of the pulse, the recording head, and the recording medium Paper interval information acquisition means for acquiring information about the distance between the paper, ink droplet ejection speed detection means for detecting speed information of ink droplets ejected from the recording head, and drive for ejecting ink from the recording head According to the adjusting means capable of adjusting the timing, the pulse interval time, the inter-paper distance information and the ink droplet velocity information, It is achieved by an ink jet recording apparatus provided with a calculation means for calculating a shift amount of the drive timing of the serial recording head.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The mechanical configuration of the recording apparatus of this example is the same as that of the conventional example of FIG.

  FIG. 1 is a block diagram of the recording apparatus of this example.

  The recording data transferred from the host apparatus 101 is received by the I / F unit 103 in the recording control unit 102 in the recording apparatus of this example, and then sent to the recording data generation unit 104. The recording data generation unit 104 performs decompression of the compressed data, conversion of the data array, etc., converts the received data into a format that can be recorded by the recording head 105, and sends the data to the recording data transfer unit 106. As the recording head 105, for example, an ink jet recording head of a type that ejects ink using thermal energy can be used. The ink jet recording head causes film boiling in the ink in the ink flow path due to the thermal energy generated by the electrothermal transducer provided in the ink flow path, and discharges ink droplets from the ink discharge port by the foaming energy. .

  On the other hand, an encoder 109 is mounted on the carriage 108 driven by the carriage motor 107 together with the recording head 105. The encoder 109 outputs a pulse signal every time the carriage 108 moves a certain distance. The pulse signal generated by the encoder 109 passes through the LPF unit 110 in the recording control unit 102 and noise is removed, and then sent to the edge trigger generation unit 111. The edge trigger generator 111 detects a predetermined edge (encoder edge) in the received pulse signal and generates a trigger pulse. The trigger pulse generated by the edge trigger generation unit 111 is sent to the head position detection unit 112, the speed detection unit 113, and the edge trigger delay unit 114. The head position detection unit 112 detects the movement position of the recording head 105 by counting the signal sent from the edge trigger generation unit 111 with an UP / DOWN counter, and sends information to the paper gap information acquisition unit 115. The memory 116 stores information about the paper interval that is predicted in advance according to the type of recording medium, the ambient temperature, and the positions of ribs and spurs on the printing apparatus platen, and delay information that corresponds to the ink ejection speed. The acquisition unit 115 acquires delay information associated with the sheet from the memory 116 as necessary, and updates the delay information associated with the sheet to be sent to the delay value calculation unit 117. The speed detector 113 measures the interval between trigger pulses generated by the edge trigger generator 111 and transfers the value to the delay value calculator 117 as current speed information. The speed information detected by the speed detector 113 is also sent to a servo controller (not shown) that servo-controls the carriage motor 107 as necessary.

  The delay calculation unit 117 uses the paper gap information sent from the paper gap information acquisition unit 115 and the speed information sent from the speed detection unit 113 to correct the landing position of the ink droplets, as will be described later. The landing correction delay value is calculated. The edge trigger delay unit 114 delays the trigger pulse generated by the edge trigger generation unit 111 according to the landing correction delay value calculated by the delay calculation unit 117 and then records the recording timing generation unit 118 and the recording position detection unit. It outputs to 119. The recording timing generation unit 118 generates a recording timing signal obtained by converting the trigger pulse sent from the edge trigger delay unit 114 into a recording resolution, and sends the recording timing signal to the recording position information detection unit 119 and the recording data transfer unit 106. . The recording position information detection unit 119 generates position information related to the recording timing by counting signals sent from the edge trigger delay unit 114 and the recording timing generation unit 118 with an UP / DOWN counter. The position information regarding the recording timing detected by the recording position information detection unit 119 is sent to the recording position detection unit 120. The recording position detection unit 120 generates a recording start signal when the recording start position is detected from the position information, and generates a recording end signal when the recording end position is detected, and transfers the information to the recording data. Send to part 106. The recording data transfer unit 106 transfers the recording data generated by the recording data generation unit 104 to the recording head 105 in accordance with information from the recording timing generation unit 118 and the recording position detection unit 120. The recording head 105 ejects ink droplets toward the recording medium based on the information sent from the recording data transfer unit 106. Further, the ink droplet ejection speed information detection unit 121 acquires information on the ink temperature or the ambient temperature by the temperature sensor 122 on the carriage 108. The ink ejection speed information detection unit 121 estimates the ink droplet ejection speed based on the temperature information from the temperature sensor 122. In general, when the temperature of the ink is low, the viscosity of the ink is high, and the ejection speed of the ink droplet when the same energy is applied decreases. Conversely, when the ink temperature is high, the ejection speed of the ink droplets tends to increase compared to when the ink temperature is low. The ink ejection speed information detection unit 121 estimates the current paper interval information in the memory 116 and the delay information corresponding to the ink ejection speed at the timing when the change in the ink ejection speed reaches a predetermined value or more. Change according to speed information. Further, the calculation parameter A (= t3 / t2) in the delay calculation unit 117 is also changed according to the currently estimated speed information. Thereby, the correction of the landing position corresponding to the change in the ejection speed of the ink droplet is realized.

  FIG. 5 shows the waveform of an encoder generation signal (encoder signal).

  As in the case of a general digital encoder signal, an encoder generated signal is output by shifting the two waveforms of the A phase 601 and the B phase 602 by about 90 degrees in phase, and depending on the carriage moving direction, the left side in FIG. Lead phase (forward rotation) 603, or the right delay phase (reverse rotation) 604 in the figure. Therefore, for example, with the one-side edge of the A phase as the detection point, the UP / OFF of the position detection counter is detected at the detection time of the rising and falling edges of the A phase at the fixed phase of the B phase (Low level in the figure). By switching the down operation, the movement position of the carriage can be detected. More specifically, for example, at the low level of the B phase, every time the rising edge of the A phase is detected, the position detection counter is counted up, and the position detection is performed every time the falling edge of the A phase is detected. By switching the UP / Down operation of the position detection counter so as to count down the counter, the carriage movement position (recording head movement speed) can be detected from the count value of the position detection counter.

  The edge trigger generation unit 111 detects the edge of the encoder pulse as shown in FIG. 5 to generate a trigger pulse, and the speed detection unit 113 sets the trigger pulse interval (time) (also referred to as “encoder edge interval (time)”). The movement speed of the carriage is detected.

FIG. 6 is an explanatory diagram showing correction values when the scanning speed of the recording head changes. The reference speed is V701, the current speed is Vs702, the ink ejection speed is Vd703, the distance between the recording head and the recording medium is d704, the angle at which the ink droplets fly at the reference speed V701 is θ705, and the ink from the ink ejection point at that time Is the distance in the scanning direction of the recording head at the point where the ink has landed on the recording medium, and the angle at which the ink droplets fly at the current speed Vs 702 is θs 707. The recording head scan at the point where the ink has landed on the recording medium at that time If the distance in the direction is ls708,
From tanθ = V / Vd = 1 / d, l = d * V / Vd Equation 1
From tanθs = Vs / Vd = ls / d, ls = d * Vs / Vd Equation 2
The difference lx709 from the ink discharge point to the ink landing point when the recording head moves at each speed from Equation 1 and Equation 2 is:
lx = l−1s = (V−Vs) * d / Vd Equation 3
Here, the scanning speed of the recording head can be obtained by moving the edge interval of the encoder signal, that is, the distance of the encoder resolution. If the distance of the encoder resolution is Er, the time when the distance Er is moved by V701 is Tsta, and the time when the distance Er is moved by Vs702 is Ts.
V = Er / Tsta Equation 4
Vs = Er / Ts Equation 5
Assuming that the time required for the ink droplet to travel the distance d704 at the speed Vd703 is Td,
Vd = d / Td Equation 6
From Equation 3, Equation 4, Equation 5, and Equation 6, the time T710 required to move lx709 at the current speed Vs702 is
T = lx / Vs = (Ts−T) Td / Tsta Equation 7
Here, if A = Td / Tsat, then T = (Ts−Tsta) * A Equation 8
As can be seen from FIG. 6, it is possible to match the landing position of the current speed Vs 702 with the landing position 711 at the reference speed V 701 by shifting the ink discharge point of the current speed Vs 702 by time T710.
That is, it can be seen from Equation 8 that if the ink droplet ejection speed Vd 703 and the recording head reference scanning speed V701 are known, the landing position can be corrected for each detection of the current speed Vs702. In addition, the parameter A = Td / Tsat in Expression 8 is proportional to Td, and Td is the time required for the ink droplet to move the distance d704 at the velocity Vd703, and is expressed as Td = d / Vd. That is, the parameter A is proportional to the reciprocal of the ink droplet ejection speed Vd, and the correction corresponding to the ink droplet ejection speed change is possible by controlling the parameter A according to the ink droplet ejection speed change. .
FIG. 7 is an explanatory diagram showing correction values when the distance between the recording head and the recording medium changes. The recording head scanning speed is Vs801, the ink droplet ejection speed is Vd802, the angle at which the ink droplets fly is θ803, the reference inter-paper distance is d804, the distance from the ink ejection point to the ink landing point at this time is l805, If the distance between papers is ds806, and the distance from the ink ejection point to the ink landing point at that time is ls807,
tan θ = V / Vd = 1 / d = 1 s / ds Equation 9
From Equation 9, l = V * d / Vd Equation 10
ld = V * ds / Vd Equation 11
The distance difference lx808 from the ink discharge point to the landing point at each paper distance is:
lx = l−1s = V (d−ds) / Vd Equation 12
Assuming that the time required for the ink droplets to pass through the paper interval d at the ejection speed Vd is Td, and the time required for the ink droplets to pass through the paper interval ds is Tds,
Vd = d / Td = ds / Tds Equation 13
The time T809 for moving the landing deviation amount lx808 at the head scanning speed V801 is:
T = lx / V = V (d−ds) / (Vd * V)
= Td-Tds Equation 14
Equation 14 shows the time required to pass the difference between the standard paper distance d804 and the current paper distance ds806 at the ink droplet ejection speed Vd802. It is proportional to the reciprocal of the discharge speed. In other words, by applying the value of Expression 14 corresponding to the change amount between the papers and the change in the ink droplet ejection speed, it is possible to correct the landing position corresponding to the paper-to-paper fluctuation and the ink ejection speed change.
The delay value due to the sheet-to-sheet variation shown in Expression 14 is related only to the amount of change between sheets and the ejection speed of the ink droplets, and is independent of the scanning speed of the recording head. In other words, the delay value due to the scanning speed fluctuation of the recording head and the delay value due to the paper interval fluctuation are independent, and as shown in FIG. 10, the ink droplet ejection speed Vd1301, the recording head reference scanning speed V1302, and the current scanning speed Vs1303. By reflecting the delay value T1305 at the reference paper distance d1304 and the sum of the delay value t1307 at the current paper distance ds1306 to the reference paper distance d1304, the current recording head is reflected. An ink droplet can be landed on the ideal landing position 1308 with respect to the current inter-paper distance ds 1306 at the scanning speed Vs 1303.

FIG. 8 shows a flowchart for explaining the basic operation of this embodiment. First, when the operation start timing occurs (s901), it is determined whether the delay calculation mode is ON / OFF (s902). Here, if the delay calculation mode is OFF, no operation is performed and the processing is terminated as it is (s903). If the delay calculation mode is ON, it is next determined whether or not it is the ink droplet discharge speed information acquisition timing (s904). This timing is, for example, a timing for starting a new printing, every printing page, every fixed time after the power is turned on, or the like. Here, in the case of the ink droplet ejection speed information acquisition timing, the ink droplet ejection speed acquired after acquiring the ink droplet ejection speed information (s905) changes more than a specified value with respect to the ink droplet ejection speed used for the current calculation. A determination is made as to whether it is present (s906). If the acquired ink droplet ejection speed has changed by more than the specified value, the parameter A corresponding to the acquired ink droplet speed information is updated and δt in the memory is updated (s907). Next, it is determined whether it is the paper interval information acquisition timing (s908). In the case of the paper gap information acquisition timing, the paper gap information is acquired (s909), and δt used for the calculation is updated (s910). Further, the paper interval correction value update timing is determined (s911). In the case of the paper interval correction value update timing, t4 + δt is calculated (s912), and the value of t4 is updated. Then, the correction value calculation is performed (s913) and the process ends. (S903)
Here, a method for acquiring the paper gap information, that is, a method for updating δt, may be a method in which all δt is stored in the memory 116 for each scanning position of the recording head. In this case, if δt is recorded for every scanning position of all the recording heads, it is necessary to record a huge amount of δt in the memory. Further, a method of approximating and changing the change of δt as a first-order or n-th order function is conceivable. FIG. 10 is a diagram for explaining the relationship between the sheet interval and δt when a linear function (proportional function) is used. Assume that the recording medium 1102 has a relationship as shown in the figure with respect to the scanning position 1001 of the recording head. In this case, the gap between the papers changes so as to follow the scanning of the recording head. Here, the paper gap correction value t4 changes by one function (proportional function) according to the paper gap information and the scanning position of the recording head, that is, is obtained by adding or subtracting a proportional constant δt to a preset paper gap correction value t4. . At that time, the proportionality constant δt is switched by dividing the area according to the degree of fluctuation between sheets. For example, in the region (1) 1003 in which the gap between the sheets gradually changes in FIG. 10, the proportionality constant is set to δt1004. In the region (2) 1005 where the sheet-to-sheet variation is slightly steeper than that in the region (1) 1003, the proportionality constant is slightly increased and is changed to δt ′ (δt <δt ′) 1006. Further, in the region (3) 1007 where the sheet-to-sheet variation is abrupt, the proportionality constant is further increased to be changed to δt ″ (δt ′ <δ ″) 1008. In this way, when the paper constant fluctuation correction value t4 is calculated by changing the proportionality constant δt, the calculation is executed so that the paper gap information is changed as indicated by the corrected recording medium position 1009 indicated by the broken line in the figure, and the actual recording is performed. It is possible to vary the inter-paper variation correction value so as to follow the change of the medium relatively well. In this method, it is sufficient to store only the initial value of the paper gap fluctuation correction value t4, the proportional constant δt for each area, and the position information for switching the proportional constant in the memory 116, and good paper gap fluctuation with less information. Correction calculation can be realized. Further, by adjusting the value of δt in the memory 116 to the current ink droplet ejection speed, it is possible to cope with a change in the ink droplet ejection speed.

  As described above, even when the scanning speed of the recording head, the distance between the recording head and the recording medium, and the ejection speed of the ink droplets fluctuate, the obtained current recording head scanning speed information and an appropriate paper gap correction value are obtained. If the ink droplet ejection timing is controlled based on t4 and the estimated current ink droplet ejection speed information, the ink droplet can always be ejected to the ideal landing position.

(Other embodiments)
In the above embodiment, the ink droplet ejection speed is estimated from the ink or ambient temperature, but it can also be estimated from the total number of prints and the total number of ink droplets ejected from the nozzles of the recording head. In general, as ink is repeatedly ejected from a new recording head, the ink droplet ejection speed decreases. The ink droplet ejection speed is estimated using the total number of prints and the total number of ink droplet ejections as parameters for determining the usage degree of the recording head.

  It is also possible to estimate the ink droplet ejection speed in consideration of both the recording head usage and the ink temperature.

FIG. 3 is a block configuration diagram of a main part of a control system in the inkjet recording apparatus of the present invention. 1 is a perspective view of a main part of mechanical components in an ink jet recording apparatus to which the present invention can be applied. FIG. 4 is a diagram for explaining the flying direction of ink droplets in an inkjet recording apparatus. FIG. 4 is a diagram illustrating a change in ink droplet landing position when the speed of an ink droplet ejected from a recording head changes. It is explanatory drawing of the output signal of an encoder. FIG. 5 is a diagram for explaining ink droplet landing position correction based on a recording head scanning speed variation in an inkjet recording apparatus. FIG. 4 is a diagram for explaining ink droplet landing position correction due to a change in the distance between the recording head and the recording medium in the inkjet recording apparatus. The flowchart for demonstrating the basic operation | movement of this invention. FIG. 6 is a diagram for explaining a method for updating a proportional constant δt for inter-sheet fluctuation correction value considering changes in the distance between the recording head and the recording medium. FIG. 4 is a diagram for explaining ink droplet landing position correction when both the recording head scanning speed and the distance between the recording head and the recording medium change in the ink jet recording apparatus.

Explanation of symbols

101 Host device 109 Encoder 111 Edge trigger generation unit (edge detection unit)
DESCRIPTION OF SYMBOLS 112 Head position detection part 113 Speed detection part 114 Edge trigger Delay part 115 Paper gap information acquisition part 116 Memory 117 Delay value calculation part 118 Recording timing generation part 119 Recording position information detection part 120 Recording position detection part 121 Ink droplet discharge speed detection part 122 Temperature sensor 205 Carriage 206 Carriage motor 208 Recording head

Claims (5)

In an inkjet recording apparatus that uses a recording head capable of ejecting ink and performs recording on the recording medium by ejecting ink from the recording head while relatively moving the recording head and the recording medium.
An encoder that outputs a pulse each time the recording head and the recording medium move relative to each other by a certain amount;
Detecting means for detecting an interval time of the pulse;
An inter-paper information acquisition means for acquiring inter-paper distance information between the recording head and the recording medium;
Ink droplet discharge speed detection means for detecting speed information of ink droplets discharged from the recording head;
An adjusting means capable of adjusting a driving timing for discharging ink from the recording head;
A calculation means for calculating a shift amount of the drive timing of the recording head according to the interval time of the pulse, the distance information between the papers, and the velocity information of the ink droplets;
Control means for controlling the adjusting means according to the calculation result of the calculating means;
An ink jet recording apparatus comprising: The calculation means has an interval time of the pulses detected by the detection means as t1, an interval of the pulses at a speed higher than an assumed maximum speed as a reference interval time t2, and a reference paper more than an assumed longest paper interval. Interval d, the ejection speed of the ink ejected from the recording head Vd, the time required for the ink ejected from the recording head to pass through the reference sheet interval d t3 (= d / Vd), and the parameter A ( = t3 / t2), when the difference δd between the reference sheet interval d and the current sheet interval ds is t4 (= δd / Vd) when the time required for the ink ejected from the recording head to pass is The delay time t of the drive timing of the recording head is calculated by the following formula,
t = (t1-t2) * A + t4
The delay time t of the drive timing of the recording head is calculated by varying t1 for every change in the interval time of the pulse and t4 for every change in the sheet interval information acquired by the acquisition unit,
An ink jet recording apparatus, wherein the parameter A (= t3 / t2) and the time t4 (= δd / Vd) are varied every time a change in the ink ejection speed Vd is detected. The speed information of the ink droplets ejected from the recording head is obtained by estimating the speed information of the ink droplets ejected from the recording head by acquiring a parameter correlated with the speed information.
An inkjet recording apparatus, wherein the parameter A (= t3 / t2) is updated and the time t4 (= δd / Vd) is updated.   An ink jet recording apparatus using an ink temperature or an ambient environment temperature of the recording head as a parameter correlated with the speed information. An ink jet recording apparatus using the total number of ink droplets ejected from each nozzle of the recording head or the number of printed sheets as a parameter correlated with the speed information.

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