JP2015217632A - Inkjet recording device and inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording device that can reflect a heat storage state of a head (an inner temperature of the head) being recorded so as to appropriately set speed for record scanning and perform preferably image recording while suppressing deterioration in through-put.SOLUTION: The inkjet recording device obtains first information at first timing after precedent scanning, obtains second information at second timing after predetermined time elapses after the first timing, and determines speed for scanning on the basis of the first information and the second information.

Description

  The present invention relates to an ink jet recording apparatus and an ink jet recording method for performing recording by discharging ink onto a recording medium.

  An ink jet recording apparatus transports a recording medium in a direction crossing an operation (recording scanning) for scanning a recording head such as paper with a recording head having an ejection port for ejecting ink, and a direction in which the recording head is scanned. The conveyance operation is repeated to form an image. The recording head includes a recording element for generating energy used for ejecting ink and a recording element substrate provided with an ejection port for ejecting ink. The recording element substrate includes alumina having an ink supply path, It is fixed to a support member such as resin. The ink undergoes film boiling due to the thermal energy generated by the recording element provided so as to correspond to the ejection port, and is ejected from the ejection port by the pressure of bubbles generated at this time, and landed on the recording medium.

  Even when a voltage pulse in accordance with image data is applied to a recording element, normal ejection of ink droplets from each recording element is not generally referred to as non-ejection. When the ejection is repeated continuously with a high duty, the thermal energy generated by the ejection accumulates in the recording head, and the temperature of the recording head is gradually raised. When the recording head is in an excessive heat storage state, there is a concern that the volume of ink droplets that are ejected increases due to an increase in the ink temperature, and the refilling of ink is not in time, causing the above-mentioned non-ejection.

  Japanese Patent Laid-Open No. 2004-151867 reduces the speed of recording scanning so that ink supply is in time when the temperature information of the recording head and the high-duty image equal to or higher than the threshold set by the recording head temperature from the image data information are obtained. Is disclosed.

JP-A-2005-246641

  On the other hand, not only the ink temperature in the recording element but also the ink temperature in the ink supply path to the recording element is greatly related. When the ink temperature in the ink supply flow path is low and the viscosity is high, the fluidity of the ink is lowered, so that the supply performance is lowered and the ejection becomes unstable. On the other hand, when the ink temperature in the ink supply path is high and the viscosity is low, the fluidity of the ink is high, and the ejection is stabilized.

  In Patent Document 1, the detected temperature of the recording element substrate is set as the temperature of the recording head, and the speed of the next recording scan is controlled accordingly. For example, even if it is detected that the recording element substrate is at a high temperature, there is a possibility that the temperature of the ink in the ink supply path is relatively high, the viscosity is low, and refilling is in time. Even in such a case, there is a possibility that the speed of recording scanning is limited. The present invention has been made in view of the above, and provides an ink jet recording apparatus and an ink jet recording method capable of controlling a recording speed by reflecting ink supply characteristics from an ink supply path according to temperature. It becomes possible.

  The present invention is provided with a recording element substrate including a recording element that generates energy used for ejecting ink, and a supply path for supporting the recording element substrate and supplying ink to the recording element substrate. A recording head provided with a supporting member, and the recording head is scanned with respect to a recording medium in a predetermined direction at a predetermined speed, and the recording element is driven to eject ink. A temperature corresponding to the temperature of the recording element substrate from a control means for controlling the recording head to record an image on a recording medium and a sensor for detecting the temperature of the recording element substrate provided on the recording element substrate An ink jet recording apparatus comprising: a first acquisition unit configured to acquire information; wherein the first acquisition unit includes a first timing after the preceding scan until the next scan. To obtain the first temperature information at a second time after the predetermined time has elapsed from the first timing and until the next scanning, The control unit may determine the predetermined speed for performing the next scan based on the first temperature information and the second temperature information.

  As described above, according to the present invention, the temperature of the ink supplied to the recording element substrate can be reflected in the setting of the speed of the recording head in the recording scan. Accordingly, it is possible to provide an ink jet recording apparatus and an ink jet recording method capable of controlling the recording speed by reflecting the ink supply characteristic from the ink supply path according to the temperature.

1 is a schematic diagram of an ink jet recording apparatus and a recording head according to the present invention. It is a flowchart for demonstrating the flow of the temperature T3 calculation process of a supporting member. 1 is a schematic diagram of an ink jet recording apparatus and a recording head according to the present invention. FIG. 2 is a schematic plan view of a recording element substrate and a cross-sectional view of the recording element substrate according to the present invention. 2 is a block diagram showing a control system of the ink jet recording apparatus according to the present invention. FIG. It is a figure for demonstrating the temperature acquisition timing which concerns on this invention. It is a block diagram explaining the structure of the process of the image data which concerns on this invention. 3 is a flowchart for explaining a process according to the first embodiment. It is a figure for demonstrating the dot count method of data. 3 is a scanning speed threshold table according to the first embodiment. 10 is a flowchart for explaining a process according to the second embodiment. 10 is a scanning speed threshold value table of Example 2. 10 is a flowchart for explaining a process of the third embodiment. It is a figure for demonstrating the division | segmentation method of the printing scanning frequency | count.

  The ink jet recording apparatus can be used for performing a recording operation on a recording medium by discharging ink. Specific examples of applicable equipment include office equipment such as printers, copiers, and facsimile machines, and industrial production equipment. By using such an ink jet recording apparatus, recording can be performed on various recording media such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, and ceramics.

  “Recording” used in this specification means not only giving an image having a meaning such as a character or a figure to a recording medium but also giving an image having no meaning such as a pattern. I will do it. Furthermore, “ink” is to be interpreted widely, and is applied to a recording medium to be used for forming an image, pattern, pattern, etc., processing the recording medium, or processing the ink or the recording medium. Say liquid.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, components having the same function may be given the same reference numerals in the drawings, and the description thereof may be omitted.

(Inkjet recording device)
FIG. 3A is a schematic perspective view for explaining the internal mechanism of the ink jet recording apparatus applicable to this embodiment. The recording medium 4 is transported in the direction of arrow F (sub-scanning direction) by a transport motor (not shown) (transport operation). A guide shaft 3 is disposed in parallel along the direction perpendicular to the conveyance direction F (sub-scanning direction) of the recording medium 4 so as to be along the paper surface of the recording medium 4. The carriage 1 (scanning means) on which the recording head 5 is mounted is reciprocated (reciprocated scanning) in the direction of the arrow S (main scanning direction) in the figure by driving a carriage motor (not shown) while being supported by the guide shaft 3. To do. Further, the ink jet recording apparatus is provided with an ink tank (not shown), and this ink is supplied to the recording head 5 through an ink path.

  When the carriage 1 performs reciprocating scanning, the recording head 5 discharges ink according to the recording data, thereby recording on the recording medium (recording operation). Then, image formation on a recording medium is performed by repeatedly performing such a recording operation and a conveying operation. In the present embodiment, a so-called bidirectional recording method is employed in which recording is performed on a recording medium by ejecting ink both when the recording head 5 moves along the forward path and when the recording head 5 moves along the backward path. When scanning with one recording by the recording head 5 is performed, the recording medium 4 is transported by a predetermined amount by a transport motor (not shown). This is repeated, and recording is performed by scanning the recording medium a plurality of times with the recording head.

(Recording head)
FIG. 3B is a schematic perspective view of the recording head 5 mounted on the carriage 1 of the ink jet recording apparatus shown in FIG. FIG. 3C is a schematic view of a discharge port forming surface which is a surface facing the recording medium 4 of the recording head. A plurality of ejection ports 30 (indicated by one line segment for simplicity) are provided on the surface of the recording element substrate 6 so as to form a row. The recording element substrate 6 is fixed to a support member 38 such as alumina or resin by an adhesive. An electrical wiring member 600 is provided around the recording element substrate 6 on the support member 38. Each recording element substrate 6 is electrically connected to the electric wiring member 600 and performs communication using signals with the print head via the electric wiring member 600.

  FIG. 4A is a schematic top view of the recording element substrate 6 mounted on the recording head.

  Six recording element substrates 6 are mounted on the recording head 5 in order to perform a recording operation using six types of ink. As shown in FIG. 4A, each recording element substrate 6 is provided with four ejection port arrays in which a plurality of ejection ports 30 are arranged along the sub-scanning direction. Specifically, four rows of 1280 ejection port rows arranged at 600 dpi (dot / inch) are provided, and two adjacent rows are arranged in a direction shifted by 1200 dpi. A plurality of temperature detection sensors 20 for measuring the temperature of the recording element substrate 6 are provided on each recording head substrate. The sensor 20 is formed of, for example, a semiconductor, and the electrical resistance is acquired on the recording device side as information corresponding to the temperature. And the temperature control mentioned later is performed according to the temperature corresponding to the temperature information obtained by the sensor. Hereinafter, the temperature of each recording element substrate 6 measured by the temperature detection sensor 20 is also referred to as a substrate temperature.

  FIG. 4B is a cross-sectional view schematically showing the state of the cut surface when the recording element substrate 6 of FIG. 4A is cut vertically along A-A ′. FIG. 4C is an enlarged view of the energy generating element 34 shown in FIG.

  As shown in FIG. 4B, the base member 31 is in contact with a flow path member 35 that forms an ejection port 30 corresponding to each energy generating element that generates energy used to eject ink. Is provided. As the energy generating element, an energy generating element or a piezoelectric element that generates thermal energy can be used. Further, when the flow path member 35 and the base 31 are in contact with each other, a flow path 36 communicating with each discharge port 30 is formed between the flow path member 35 and the base 31, and between the adjacent flow paths 36. A partition wall 37 is formed. The temperature detection sensor 20 is provided on the surface of the base 31.

  A heat storage layer 401, a heat generating material layer 402, and a pair of electrode layers 403 are stacked over a silicon substrate 400 provided with a driving element such as a transistor. The heat storage layer 401 can be provided with an insulating material containing silicon as a main component, the heat generating material layer 402 can be provided with a material that generates heat when energized, such as TaSiN, and the pair of electrode layers 403 are energized. It can provide with the aluminum etc. which become this electrode. A portion of the heat generating material layer 402 positioned between the pair of electrode layers 403 is used as the energy generating element 34.

  An insulating layer 404 made of an insulating material containing silicon as a main component is laminated on the heat generating material layer 402 and the pair of electrode layers 403 to protect the energy generating element 34 from ink or the like. Furthermore, a protective layer 405 made of a metal material such as Ta is provided on the insulating layer 404 corresponding to the energy generating element 34 in order to protect the energy generating element 34 from cavitation that occurs when bubbles disappear. Yes.

  The ink supplied from the ink supply path 2 of the ink jet recording apparatus to the inside of the recording head 5 through the joint portion 7 (FIG. 3B) passes through the ink supply path 39 in the support member 38 and passes through the recording element substrate 6. To the ink supply port 32. Then, it is conveyed to the upper side of the energy generating element 34 through the flow path 36. Most of the heat generated by the ejection of the energy generating element 34 moves to the support member 38 that fixes the recording element substrate. This support member is made of a material such as alumina, and has a large heat capacity with respect to the recording element substrate 6, and therefore has the property of depriving the heat generated in the recording element substrate 6 and storing the heat.

  Further, by driving the energy generating element 34 of the recording head by a recording signal received from the ink jet recording apparatus, a driving pulse is applied to the energy generating element 34 to energize and generate heat. The ink on the energy generating element 34 is boiled by this thermal energy and foams, and the ink is ejected from the ejection port by the pressure of the bubbles generated at this time, and the recording operation is performed.

(Control configuration)
FIG. 5 is a block diagram showing a control configuration of the ink jet recording apparatus. The control system 24 of the ink jet recording apparatus is provided with a CPU 200, a ROM 201, an RM 202, and a gate array 203. The ROM 201 is used as a storage unit that stores a program executed by the CPU 200 and can be used to store a drive pulse table for performing ejection control. The RAM 202 is storage means that can be used to temporarily store various data (image data, recording signals supplied to the recording head, etc.). The gate array 203 is used for supplying a recording signal to the recording head 5, and is also used for data transfer between the interface 23, the CPU 200, and the RAM 202.

  In addition, a communication interface 23 that performs a communication interface operation with an external device 22 such as a host computer is provided, and the CPU 200 and the ROM 201, the RAM 202, or the communication interface 23 are connected to each other via a bus.

  Furthermore, a head driver 25, a recording head 5, and a power supply circuit 29 that functions as a recording head power supply circuit are provided. The head driver outputs a control signal under the control of the CPU 200 and performs drive control of the recording head 5 that is supplied with the head voltage VH from the power supply circuit 29. In this case, the power supply circuit 29 is supplied with an external voltage V from an external power supply. The head driver performs control (supply / cut-off control) when the head voltage VH of the recording head 5 is supplied as drive power by inputting the power control signal PC to the power circuit 29 under the control of the CPU 200.

  The motor driver 26 is used to drive the carriage motor 8 in order to move the recording head 5 to a predetermined recording position in the main scanning direction in accordance with a signal output from the control system 24. Similarly, the recording head driver 25 drives the recording head 5 in accordance with the recording signal output from the control system 24. Further, the motor driver 26 drives the transport motor 9 in accordance with the signal output from the control system 24, and performs the recording medium transport operation.

  Further, the recording head 5 includes a temperature detection sensor 20 for detecting the temperature of the recording head, and an EEPROM 21 for storing characteristics acquired at the time of factory inspection, such as ejection amount, energy generating element, and wiring resistance. Is provided.

  Further, the thermistor 28 for detecting the environmental temperature where the recording apparatus is installed is installed in the apparatus main body.

  Here, the gate array 203 and the CPU 200 of the control system 24 convert the image data received from the external device 22 via the interface 23 into recording data and store it in the RAM 202. Further, the control system 24 drives the motor drivers 26 and 27 and the recording head driver 25 in synchronization, so that the recording operation of the recording head 5, the transport operation of the recording medium, and the reciprocation of the recording head 5 in the main scanning direction are performed. Move to form an image on the recording medium.

  In the present embodiment, since the temperature sensor for detecting the temperature of the recording head is installed in the vicinity of the recording element on the recording element substrate, the temperature of the recording element substrate accompanying recording can be detected to some extent accurately. However, it is difficult to detect the temperature of the support member 38 during the recording operation, and it is difficult to accurately detect the heat storage state in the recording head, although it is possible to detect the temperature change accompanying recording. For example, it is detected that the temperature at the first scan from the start of recording when recording a high-duty image and the temperature at the 100th scan from the start of recording when recording a low-duty image are both 80 ° C. And Here, FIG. 1 is a graph showing the difference in the heat storage state of the recording head, and shows the temperature in the thickness direction of the recording element substrate in the two states described above. Even if the temperature from the surface of the recording element substrate to the depth of about several hundred μm is the same, the amount of heat stored in the member for fixing the recording element substrate in a region several millimeters deeper than that is the same as in the first scan. It is very different at the 100th scan. At this time, although the temperature of the recording head in the 100th scan of the low duty image recording is higher, the temperature sensor of the recording element substrate cannot detect the difference in the state.

As described with reference to FIG. 1, when the recording is continued continuously, the heat generated in the recording element is gradually diffused and stored in the head, and the support member 38 is heated. The temperature rises. As shown in FIG. 2B, since the support member 38 is in contact with the ink in the ink supply path 39, the temperature of the ink supplied to the recording element via the support member 38 also rises. When the ink temperature in the ink supply path 39 is low, the ink viscosity is high and the fluidity of the ink flowing through the flow path is low. For this reason, particularly when a high-duty image is printed, the ink supply performance to the printing element in the printing element substrate is lowered, and the ejection becomes unstable. For this reason, it is desirable that the ink is supplied promptly from the ink supply path. On the other hand, when the ink temperature in the recording element substrate is low, the ink supply performance in the recording element substrate is improved and the ejection is stabilized.

Ink Temperature and Ink Supplyability in Recording Element Substrate When the ink temperature in the recording element substrate filled in the flow path 36 in FIG. 4C is low, the ink viscosity is high and the foam size is reduced, resulting in ejection. The volume of ink droplets to be reduced is reduced. On the other hand, when the temperature is high, the ink viscosity is low, and even when the same energy is applied to the energy generating element 34, the size of the foam increases, and as a result, the ejected ink droplets increase. Therefore, when the ink temperature in the recording element is high, the time required to refill the ink in the recording element that has decreased due to ejection becomes longer, the ink supply performance to the recording element decreases, and ejection becomes unstable. . On the contrary, when the ink temperature in the printing element substrate is low, the ink supply performance is improved and the ejection is stabilized.

Example 1
In this embodiment, the temperature is detected by the temperature detection sensor 20 provided on the recording element substrate 6 of the recording head, and the temperature of the support member 38 is calculated based on the temperature change after a predetermined time elapses of the detected temperature. . Further, in addition to detecting the temperature by the temperature detection sensor 20 before the start of the recording scan, the recording data is dot-counted for each unit area, the number of times of driving the recording element is detected, the temperature information of the discharge port, the support member A control for changing the recording scanning speed based on the temperature information and the drive count information will be described.

  FIG. 2 is a flowchart for explaining the flow of the temperature T3 calculation process of the support member.

  First, in S101, a first temperature T1 that is a detection value of the temperature detection sensor 20 is acquired. Subsequently, in S102, a second temperature T2 that is a detection value of the temperature detection sensor 20 after the elapse of a predetermined time t from the acquisition of T1 is acquired. Next, a temperature T3 corresponding to the temperature of the support member is calculated based on T1 and T2, and the process ends.

  Next, the acquisition timing of the first temperature T1 and the second temperature T2 will be described with reference to FIG.

  FIG. 6A shows the transition of the detected temperature of the temperature detection sensor 20 when an image with a 20% duty for each color is bidirectionally recorded. The number of recording scans is 20, and the time required for acceleration / deceleration and reversal of the carriage 1 between each recording scan is about 0.3 seconds. The head temperature rises due to ejection during image recording, and the head temperature falls during ejection pause when the carriage 1 is reversed.

  When the recording scan is repeated, the temperature of the entire head including the supporting member inside the head rises. As a result, the detection value of the temperature detection sensor 20 gradually increases while repeating the recording with a constant duty. Go.

  FIG. 6B shows a change in the output value of the temperature detection sensor 20 when attention is paid to the 14th print scan and the 15th print scan in FIG. 6A. The first temperature T1 is acquired at a timing after the end of the preceding fourteenth scanning scan (S101). The time required for detection by the head temperature detecting means of this embodiment is 50 ms. Next, the second temperature T2 is acquired at a timing after elapse of a predetermined time t seconds from the first temperature acquisition (S102). In this embodiment, t = 0.1 seconds. The time required for detecting the head temperature and the predetermined time t are not limited to the above-described settings, and may be set to optimum values depending on the actual system and configuration. Also, the acquisition of the first temperature T1 and the second temperature T2 needs to be within a non-driving period required for reversing the recording scanning direction. In addition, the first temperature T1 is acquired at the timing after the end of the printing scan, but may be acquired at the timing before the end of the recording scan if the detected temperature is not affected. For example, no discharge is performed in the vicinity of the end of the print scan, or if it is a low-duty print and the detected temperature is hardly affected, there is no problem even if it is detected at the timing before the end of the print scan. Since the detection of the second temperature T2 is intended to measure the change in the detected temperature from the first temperature T1, it is desirable to carry out the measurement in the non-driving period. 6B is a temperature detected by the temperature detection sensor 20 acquired in step 203 of a recording scanning speed determination process (FIG. 9) described later. The temperature T0 is acquired at the timing of executing the recording scanning speed determination process before starting the recording scanning. In FIG. 6B, the acquisition timings of the second temperature T2 and the temperature T0 are separated, but it is possible to set t = 0.3, acquire T2 and T0 at the same time, and set T2 = T0.

Next, a method for calculating the support member temperature T3 from the acquired first temperature T1 and second temperature T2 will be described (S103).
The support member temperature T3 is T3 = T2 / (1-exp (A * t))-T1 * exp (A * t) / (1-exp (A * t)) Formula (1)
T3: Support member temperature T1: First temperature T2: Second temperature exp (A * t): 0.633 (thermal constant of recording head)
A: Thermal diffusion coefficient (thermal conductivity)
t: Calculated using the time formula (1).
This relational expression represents a phenomenon in which the temperature changes as the heat of the recording element substrate moves to the support member. The temperature of the support member can be calculated from the first temperature and the second temperature. It can be said that the greater the degree of change from the first temperature to the second temperature, the smaller the heat storage state of the support member 38 and the lower the temperature of the support member 38.

  In this embodiment, most of the heat generated in the recording element substrate moves to the support member to which the recording element substrate is fixed. Therefore, the transfer of heat to the atmosphere and other head members is ignored, but the above relationship A term that considers heat dissipation to the atmosphere may be added to the equation.

  The thermal self constant exp (A * t) of the recording head of this embodiment is 0.633. This is a constant that varies depending on the material, volume, and structure of the head member. In order to obtain the thermal time constant, as shown in FIG. 6B, after the temperature rise by discharge is measured, the falling curve of the detection sensor temperature is measured, and at the same time, the temperature of the support member can be obtained from the equation (1). . Here, A represents the thermal diffusion coefficient. In this embodiment, A represents the diffusion coefficient when the silicon and alumina members are added together. Further, t represents the difference between the time when T2 is measured and the time when T1 is measured.

  In the case of the example shown in FIG. 6B, since the support member temperature T3 is 68.0 ° C. for the first temperature T1 and 66.4 ° C. for the second temperature T2, T3 is 63.6 ° C. from the above relational expression. Is calculated.

  If the recording element is in a non-driven state for a certain period of time, if the heat is completely diffused to the support member, the temperature of the support member becomes substantially equal to the temperature of the recording element substrate. It takes some time.

  In the method for detecting the temperature of the support member of this embodiment, the head internal temperature can be calculated at a relatively high speed if there is a non-driving period of the printing element during the printing operation. In the serial scan type ink jet printer, the technique of the present invention can be said to be a very effective method in that the temperature of the supporting member inside the recording head can be periodically acquired during recording.

  However, this is not limited to a serial scan type ink jet printer. For example, even in a full line type ink jet printer having a recording head (line head) having a size larger than the paper width, this embodiment can be applied as long as the recording element is not driven during the recording operation.

  Further, the acquisition timing of the second temperature (when the predetermined time t seconds has elapsed since the first temperature acquisition) can be arbitrarily set according to the actual system. For this reason, the head internal temperature can be acquired as the support member temperature T3 without affecting the previous recording operation such as a decrease in recording speed. The support member temperature T3 is calculated in the manner described above.

  FIG. 7 is a block diagram illustrating a configuration of processing according to the first embodiment of the present invention. First, input multi-value RGB data 301 is transferred from the external device 22 via the interface 23. In the CPU of the control system 24 of the recording apparatus, conversion processing from the multi-value RGB data 301 to the multi-value CMY data 302 is performed. The converted CMY data 302 is quantized into binary CMY data 303 by a predetermined quantization method. This binary CMY data is dot data for recording dots.

  FIG. 8 is a flowchart for explaining the flow of processing for determining the recording scanning speed performed before the start of recording scanning. Here, in this embodiment, the recording resolution in the scanning direction of the recording head is 1200 dpi, and the scanning speed of the recording head is 20 inches / s. Note that the drive frequency of the recording head in the case of 20 inches / s is 1200 × 20 = 24 kHz.

  In step 201, first, the recording data corresponding to one bandwidth of the next recording scan is divided into a plurality of blocks, and dot count of the recording data is performed for each block. As a result, it is possible to acquire ink amount information relating to the ink amount recorded in the next recording scan. Subsequently, the support member temperature T3 is acquired. (S202). Next, the current temperature T0 is acquired (S203). Subsequently, the threshold number of dots corresponding to T0 and T3 is acquired with reference to the scanning speed threshold table (S204). In step 205, the dot count value is compared with the threshold dot number for each dot count block. If even one block exceeds the threshold, the process proceeds to step 207 and the recording speed is set to 12.5 inch / s (driving frequency 15 KHz). change. If there is no block exceeding the threshold value in step 205, the process proceeds to step 206, and the recording scanning speed is not changed and the speed is maintained at 20 inches / s. Recording is performed at the finally determined recording scanning speed, and the process is terminated (S208).

  Next, a method for dot-counting recording data corresponding to one bandwidth in S201 in FIG. 8 will be described with reference to FIG. FIG. 9 is a diagram schematically showing a dot count method for data for one bandwidth recorded by the recording head 5. The area of the recording paper 320 is divided into areas to be recorded in one recording scan (vertical 1280 pixels), that is, areas in units of one bandwidth. Furthermore, one band area is divided in units of 1280 × 1280 pixels. The areas (D1 to DN) divided in this way become dot count areas, and dot count is performed for each area. Note that the width of one band in the transport direction (the height of one band) matches the nozzle width in the nozzle array direction of the recording head. In this embodiment, the vertical size of the dot count area is 1280 pixels corresponding to one bandwidth. When recording is performed without using some of the plurality of nozzles of the recording head, the area corresponding to the nozzle width actually used for recording may be set to the vertical size of the dot count. .

  Next, a method for acquiring the threshold dot numbers corresponding to T0 and T3 will be described with reference to the scanning speed threshold table in S204. FIG. 10 is a scanning speed threshold table. For example, when T0 is 55 ° C. and T3 is 32 ° C., the corresponding threshold dot number in the scanning speed threshold table is 1605600. When T0 is 62 ° C. and T3 is 26 ° C., the threshold dot number is 1419900. As described above, the threshold dot number is acquired from the scanning speed threshold table based on T0 and T3.

  In the present embodiment, the method of acquiring the threshold dot number from the threshold table has been described. However, the threshold dot number may be set by a function of temperature or calculation by LUT.

  Next, a method for determining whether or not to change the recording speed by comparing the dot count value with the threshold dot number for each dot count block in S205 to S207 will be described. For example, if the dot count value of the dot count area D1 in FIG. 9 is 1504800 and the threshold dot number is 1605600, 1504800 and 1605600 are compared to determine whether the dot count value of D1 is greater than or equal to the threshold dot number. In this case, the dot count value of D1 does not exceed the threshold dot number. Similarly, the dot count value and the threshold dot number are compared in the dot count areas D2 to DN. If there is even one dot count area that exceeds the threshold dot count, there is a risk that printing will be performed at a frequency at which ejection becomes unstable, so the printing scan speed is changed to 20 inches / s (S207). If the dot count value does not exceed the threshold dot number in all the dot count areas, the recording scanning speed is maintained at 40 inches / s (S206).

  In this embodiment, the dot count has been described by taking the case of one color as an example in order to simplify the description. Even when a plurality of colors are recorded, dot count is performed for each color, the threshold dot number is obtained from the recording scanning speed threshold table set for each color, and the determination is performed in the same manner. In that case, if there is a dot count area that exceeds the threshold number of dots even in one of a plurality of colors, the process may be executed to change the recording scanning speed to 20 inches / s.

  As described above, when the support member temperature T3 is a predetermined temperature (here, 32 ° C.), the support member temperature T3 is lower in the supply path 39 than when the support member temperature T3 is lower than the predetermined temperature (here, 26 ° C.). Since the viscosity of the ink is low, the threshold dot number is increased to make it difficult to lower the recording scanning speed.

  As described above, by determining the recording scanning speed based on the head temperature, the support member temperature, and the recording duty, it is possible to record a high-quality image while minimizing a decrease in throughput.

  Moreover, in the example mentioned above, the form which calculates temperature T3 of the support member 38 using Formula (1) by S103 was demonstrated. However, for the sake of simplicity, the threshold dot number when the temperature change degree is larger than the predetermined degree is larger than the threshold dot number when the temperature change degree is a predetermined degree as follows. Alternatively, a threshold table may be determined. For example, in S103, the difference T1-T2 is obtained as the degree of temperature change from the first temperature T1 to the second temperature T2. In S204, the threshold value table is determined so that the threshold dot number when the difference value is larger than the predetermined value is larger than the threshold dot number when the difference T1-T2 is a predetermined value. May be.

(Example 2)
In the second embodiment, control for calculating the support member temperature and changing the print scanning speed based on the calculated support member temperature and the drive count information based on the print data will be described. The basic configuration is the same as that of the first embodiment, such as a method for calculating the support member temperature T3, a method in which the recording data is dot-counted for each unit region, and the number of times the recording element is driven is detected.

  FIG. 11 is a flowchart for explaining the flow of a recording scanning speed determination process performed before the start of recording scanning in the second embodiment.

  In step 301, first, print data corresponding to one bandwidth of the next print scan is divided into a plurality of blocks, and dot count of print data is performed for each block. Subsequently, the support member temperature T3 is acquired. (S302). Next, referring to the scanning speed threshold table, the threshold dot number corresponding to T3 is acquired (S303). In step 304, the dot count value is compared with the threshold dot number for each dot count block. If even one block exceeds the threshold, the process proceeds to step 306 and the recording speed is set to 12.5 inch / s (driving frequency 15 KHz). change. If there is no block exceeding the threshold value in step 304, the process proceeds to step 305, and the recording scanning speed is not changed and the speed is maintained at 20 inch / s. Recording is executed at the finally determined recording scanning speed, and the process is terminated (S307).

  Next, a method for acquiring the threshold dot number corresponding to T3 will be described with reference to the scanning speed threshold table in S303. FIG. 12 is a scanning speed threshold table in the second embodiment. For example, when T3 is 40 ° C., the corresponding threshold dot number in the scanning speed threshold table is 1376300. When T3 is 24 ° C., the threshold dot number is 1310700. As described above, the threshold dot number is acquired from the scanning speed threshold table based on T3.

  In the present embodiment, the method of acquiring the threshold dot number from the threshold table has been described. However, the threshold dot number may be set by a function of temperature or calculation by LUT.

  The process of comparing the dot count value in steps 304, 305, and 306 with the threshold dot number and determining the print scanning speed is the same as that in the first embodiment, and thus the description thereof is omitted.

  As described above, by determining the recording scanning speed based on the support member temperature and the recording duty, it is possible to record a high-quality image while minimizing a decrease in throughput.

(Example 3)
In the first and second embodiments, the processing for changing the recording scanning speed based on the head temperature information and the recording data information has been described. In the third embodiment, a method for improving ejection stability by changing the number of recording scans when recording is performed on a unit area of a recording medium by a predetermined number of recording scans will be described.

  FIG. 13 is a flowchart for explaining the flow of the determination process of the number of printing scans performed before the start of printing scanning in the third embodiment. The processing from S401 to S405 is the same as S201 and S405 of FIG.

  Hereinafter, the flow of processing for changing the number of printing scans after Step 406 will be described. In step 405, the dot count value is compared with the threshold dot number for each dot count block, and if even one block exceeds the threshold value, the process proceeds to step 407 and the number of printing scans is changed to be divided from 1 to 2 To do. If there is no block exceeding the threshold value in step 405, the process proceeds to step 406, and the number of printing scans remains one. Recording is executed at the finally determined number of recording scans, and the process ends (S408).

  Next, a method for dividing the number of print scans will be described with reference to FIG. In this embodiment, a description will be given of a method of recording data to be recorded normally in one recording scan by dividing it into two recording scans. As shown in FIG. 14A, in a normal recording scan, data for 1280 pixels corresponding to the head width is printed in one recording scan. However, if everything is recorded in one recording scan and ejection becomes unstable as a frequency, two-division printing is performed as shown in FIG. At the time of two-division printing, the recording data is divided into two recording scans. Data corresponding to half the duty of normal printing is recorded in the first recording scan, and data corresponding to the remaining half is recorded in the second recording scan without performing the transport operation. The images recorded by the two data are combined to obtain an image corresponding to the image recorded by one recording scan as shown in FIG. As shown in FIG. 14C, the print data is divided by taking the logical product of the data before division and the mask data of the division mask 1 and division mask 2 to create division data 1 and division data 2 twice. Is divided into recorded data. In this way, the recording data is divided into two recording scans to be recorded, thereby preventing the ejection from becoming unstable. In the present embodiment, an example of dividing into two printing scans has been shown, but it is of course possible to divide into two or more times by the same method. Further, FIG. 14 shows the case of 1 Pass recording, but similarly when dividing printing is performed in multipass recording of 2 Pass recording or more, the data to be recorded in one recording scan is simply divided into a plurality of times. And record it.

  By performing the divided recording as described above, a high-quality image can be recorded while minimizing a decrease in throughput as in the first and second embodiments.

Claims (13)

A recording element substrate including a recording element that generates energy used for ejecting ink; a support member that supports the recording element substrate and is provided with a supply path for supplying ink to the recording element substrate; A recording head comprising:
The recording head scans the recording medium in a predetermined direction at a predetermined speed, drives the recording element to discharge ink, and records the image on the recording medium by performing the scanning a plurality of times. Control means for controlling the head;
First acquisition means for acquiring temperature information corresponding to the temperature of the recording element substrate from a sensor for detecting the temperature of the recording element substrate provided on the recording element substrate;
An ink jet recording apparatus comprising:
The first acquisition unit acquires the first temperature information at a first timing after the preceding scan and until the next scan, and after a predetermined time has elapsed from the first timing. And the second temperature information is acquired at a second timing until the next scanning, and the control means is configured to acquire the next temperature information based on the first temperature information and the second temperature information. An ink jet recording apparatus that determines the predetermined speed for performing scanning.   The control means is a temperature of the recording element substrate from the first timing to the second timing based on the first temperature information and the second temperature information acquired by the first acquisition means. The predetermined speed for performing the next scanning when the degree of change is larger than a predetermined degree is smaller than the predetermined speed when the temperature change degree of the recording element substrate is the predetermined degree. The inkjet recording apparatus according to claim 1, wherein the predetermined speed for performing the next scanning is determined. A second acquisition means for acquiring ink amount information related to the amount of ink ejected to the unit area of the recording medium;
The control unit is configured so that the predetermined speed for performing the next scanning when the ink amount indicated by the ink amount information acquired by the second acquisition unit is larger than a predetermined threshold is the ink amount information. Determining the predetermined speed for performing the next scan so as to be slower than the predetermined speed for performing the next scan when the amount of ink shown is not greater than the predetermined threshold; and The inkjet recording apparatus according to claim 1, wherein the threshold value is determined based on the first temperature information and the second temperature information.   The determination means calculates temperature information corresponding to the temperature of the support member based on the first temperature information and the second temperature information acquired by the first acquisition means, and corresponds to the calculated temperature information. The inkjet recording apparatus according to claim 1, wherein the predetermined speed is determined according to a temperature of the supporting member.   The control means has the predetermined speed for performing the next scanning when the temperature of the support member corresponding to the calculated temperature information is a predetermined temperature, and the temperature of the support member is a predetermined temperature. 5. The ink jet recording apparatus according to claim 4, wherein the predetermined speed for performing the next scan is determined to be faster than the predetermined speed for performing the next scan in a lower case. .   The control means calculates temperature information corresponding to the temperature of the support member based on the first temperature information and the second temperature information acquired by the first acquisition means, and the calculated temperature information Based on the temperature of the corresponding support member, the threshold value when the temperature of the support member corresponding to the calculated temperature information is a predetermined temperature is the threshold value of the support member corresponding to the calculated temperature information. The inkjet recording apparatus according to claim 3, wherein the threshold value is determined so that the threshold value is increased when the temperature is lower than a predetermined temperature.   The inkjet recording apparatus according to claim 1, wherein the support member is made of alumina.   The ink jet recording apparatus according to claim 1, wherein the energy is thermal energy.   The first acquisition unit acquires the third temperature information after a predetermined time has elapsed from the second timing and at a third timing until the next scan, and the control unit includes: The inkjet according to any one of claims 1 to 8, wherein the predetermined speed is determined based on the first temperature information, the second temperature information, and the third temperature information. Recording device. A recording element substrate including a recording element that generates energy used for ejecting ink; a support member that supports the recording element substrate and is provided with a supply path for supplying ink to the recording element substrate; A recording head comprising:
The recording head is scanned in a predetermined direction with respect to the recording medium at a predetermined speed, the recording element is driven to eject ink, and an image is recorded in the same unit area of the recording medium by the predetermined number of scans. Control means for controlling the recording head to perform
First acquisition means for acquiring temperature information corresponding to the temperature of the recording element substrate using a sensor for detecting the temperature of the recording element substrate provided on the recording element substrate;
An ink jet recording apparatus comprising:
The acquisition means acquires the first temperature information at a first timing after the preceding scan and until the next scan, and after a predetermined time has elapsed from the first timing, The second temperature information is acquired at a second timing until the next scanning, and the control unit is configured to obtain the unit region based on the first temperature information and the second temperature information. An ink jet recording apparatus that determines the number of scans for recording an image.   The control means is a temperature of the recording element substrate from the first timing to the second timing based on the first temperature information and the second temperature information acquired by the first acquisition means. The predetermined speed for performing the next scanning when the degree of change is larger than a predetermined degree is smaller than the predetermined speed when the temperature change degree of the recording element substrate is the predetermined degree. The inkjet recording apparatus according to claim 10, wherein the predetermined speed for performing the next scanning is determined. A recording element substrate including a recording element that generates energy used for ejecting ink; a support member that supports the recording element substrate and is provided with a supply path for supplying ink to the recording element substrate; The recording head is scanned at a predetermined speed in a predetermined direction with respect to the recording medium, the recording element is driven to eject ink, and an image is recorded on the recording medium by performing the scanning a plurality of times. A control step for controlling the recording head and a temperature information corresponding to the temperature of the recording element substrate are obtained using a sensor for detecting the temperature of the recording element substrate provided on the recording element substrate. An inkjet recording method comprising:
In the first acquisition step, after acquiring the first temperature information at a first timing after the preceding scan and before the next scan, and after a predetermined time has elapsed from the first timing. And acquiring the second temperature information at a second timing until the next scanning, and in the control step, the predetermined temperature based on the first temperature information and the second temperature information. An inkjet recording method characterized by determining a speed. A recording element substrate including a recording element that generates energy used for ejecting ink; a support member that supports the recording element substrate and is provided with a supply path for supplying ink to the recording element substrate; The recording head is scanned at a predetermined speed in a predetermined direction with respect to the recording medium, the recording element is driven to eject ink, and an image is formed on the same unit region of the recording medium by the predetermined number of scans. Temperature information corresponding to the temperature of the recording element substrate using a control step for controlling the recording head to perform recording and a sensor for detecting the temperature of the recording element substrate provided on the recording element substrate A first acquisition step of acquiring an ink jet recording method comprising:
In the first acquisition step, after acquiring the first temperature information at a first timing after the preceding scan and before the next scan, and after a predetermined time has elapsed from the first timing. And the second temperature information is acquired at a second timing until the next scanning, and in the control step, the unit region is based on the first temperature information and the second temperature information. An ink jet recording method, wherein the number of scans for recording the ink is determined.

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