JP2012236311A - Inkjet recording apparatus and inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus capable of recording continuous images without being affected by a change in carriage speed.SOLUTION: When determined that the counted value in a counting area in a band exceeds the number of dots of threshold, flag information showing the effect is stored (S106). Then, a process of dot counting or the like is repeated until the completion of the process of all bands included in one continuous image (S107). When determined the absence of the continuous recording data, the flag information is referred to (S108), it is determined whether or not the division area exceeding the number of dots of threshold is present in the band of the continuous recording data. When the division area exceeding the threshold is present in the continuous image, the drive frequency and carriage speed of the recording head are reduced (S110).

Description

  The present invention relates to an ink jet recording apparatus and an ink jet recording method, and more particularly to control of a scanning speed of a recording head that ejects ink.

  In the ink jet recording apparatus, conventionally, a technique is known in which the carriage moving speed, which is the scanning speed of the recording head, is changed during the recording operation, and the driving frequency of the recording head is changed in accordance with the change in the moving speed. (See Patent Document 1). According to this, for example, it is possible to suppress the temperature rise of the recording head when continuously recording at a high duty, and as a result, the volume of ejected ink droplets increases and the recording density changes. It becomes possible to prevent. In addition, it is possible to prevent the ink refill from failing to be in time due to the increase of the ink droplet volume, and as a result, it is possible to prevent the occurrence of ejection failure such as deflection in the ejection direction due to refill failure.

JP-A-2005-246641

  However, in the carriage speed control described in Patent Document 1, the carriage speed may be changed in the middle of recording a continuous area on a recording medium on which an image is recorded, such as recording paper. For this reason, the image quality may appear slightly different between the image areas having different speeds, thereby deteriorating the quality of the recorded image.

  The present invention has been made to solve this problem, and an object of the present invention is to provide an ink jet recording apparatus and an ink jet recording method capable of recording continuous images without being affected by a change in carriage speed. Is to provide.

  Therefore, the present invention is an ink jet recording apparatus that performs recording by scanning a recording head that ejects ink on a recording medium, and the number of dots to be recorded by the scanning is determined once per recording head based on the recording data. Dot counting means for counting in an area on the recording medium to be recorded by scanning, and a recording medium for recording whether or not the number of dots counted by the dot counting means is greater than a predetermined threshold value by one scan of the recording head And a recording head for recording the continuous image for each continuous image in which the image indicated by the recording data is a continuous image on the recording medium in accordance with the determination result of the determination unit. Determining means for determining the scanning speed and the ejection frequency of the recording head.

  According to the above configuration, it is possible to perform continuous image recording without being affected by the change in the carriage speed.

1 is a top view showing an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of a control system of the ink jet recording apparatus illustrated in FIG. 1. FIG. 3 is a diagram illustrating data processing inside the host device 200 and the printer main body 240 shown in FIG. 2. It is a figure explaining index expansion of recording data. It is a figure which shows typically the dot count area | region of the data for 1 band recorded with a recording head. FIG. 6 is a diagram illustrating a threshold dot number set with respect to the temperature of a recording head. It is a figure which shows typically the structure for the comparison of a threshold dot number and a dot count value. It is a figure which shows the continuous image formed by the several band based on 1st Embodiment of this invention. It is a block diagram which shows the structure which concerns on the switching process of a carriage speed of embodiment of this invention. 4 is a flowchart illustrating a carriage speed switching process according to the first embodiment of the present invention. It is a figure which shows an example in the case of recording a different continuous image by the same scanning. It is a figure which shows the continuous image formed by the several band based on 2nd Embodiment of this invention. It is a flowchart which shows the switching process of the carriage speed which concerns on the 2nd Embodiment of this invention. It is a figure which shows the continuous image formed by the several band based on 3rd Embodiment of this invention. It is explanatory drawing of 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a top view showing an ink jet recording apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 2 denotes an apparatus main body including a paper transport system unit for transporting a recording medium such as a recording paper, and 1 denotes a carriage. The carriage 1 moves with the recording head 5 mounted thereon, thereby enabling the recording head 5 to scan the recording medium. Specifically, the carriage 1 is guided and supported so as to be movable along the guide shaft 11, and can reciprocate by a driving force transmitted via the belt 13. The recording head 5 ejects a total of six colors of ink including light cyan (LC) and light magenta (LM) in addition to cyan (C), magenta (M), yellow (Y), and black (K). Each consists of a separate recording head. In the present embodiment, each recording head 5 is provided with a heater in an ejection port for ejecting ink, and ejects ink by the pressure of bubbles generated in the ink when the heater generates heat in response to an ejection signal. . Each recording head 5 of this embodiment includes a temperature sensor for detecting the temperature of the recording head.

  In applying the present invention, it is needless to say that the ejection method of the recording head is not limited to this bubble. Any method may be used as long as it generates a certain amount of heat in accordance with driving for ink ejection, such as a piezo element. The example shown in FIG. 1 relates to an example in which six colors of ink are used, but the ink jet recording apparatus applicable to the present invention may be an apparatus that uses at least one color of ink. For example, in the case of a monochrome recording apparatus, only one color of black (K) may be used. As a color recording apparatus, four colors of cyan (C), magenta (M), yellow (Y), and black (K) are used. Color can also be used.

  30A and 30B indicate a recovery mechanism. The recovery mechanisms 30A and 30B have caps and perform a suction operation using a pump (not shown) of each recording head 5 as a drive source. The recovery mechanisms 30A and 30B include a wiping mechanism (not shown) for performing the wiping operation of the ejection port surface of each recording head 5, and further includes a cap for protecting the recording head when the recording head is not used. Reference numeral 31 denotes a preliminary ejection ink receiving box that receives ink ejected by the preliminary ejection operation of each recording head 5.

  In the above apparatus configuration, the carriage 1 moves in a direction (main scanning direction) along the guide shaft 11 in order to record on a recording medium sent by a paper transport unit (not shown) when recording data is received from the host apparatus. Controlled. Thereby, each recording head 5 is scanned, and an image for one band is recorded on the recording medium. The recording medium is transported by the paper transport unit for one band in the direction orthogonal to the carriage 1 (sub-scanning direction). An encoder film 12 for detecting the movement position of the carriage is disposed along the movement path of the carriage 1, and an encoder sensor mounted on the carriage 1 knows the position of the carriage based on a signal for detecting this. be able to. Further, based on the position detection of the encoder, the movement of the carriage 1 to the home position (in this embodiment, the position facing the recovery mechanism) is controlled.

  Each recording head 5 has 1280 ejection openings arranged at a density of 1200 dpi (dots / inch) in the sub-scanning direction. As described above, a heater (electrothermal converter) for locally heating the ink to cause film boiling and ejecting the ink by the pressure is provided in the ink liquid path communicating with each discharge port. Is provided.

  FIG. 2 is a block diagram showing a configuration of a control system of the ink jet recording apparatus shown in FIG. In FIG. 2, the printer control unit 220 is controlled by an MPU (Micro Processor Unit) 221 in accordance with a program recorded in the ROM 227. The RAM 228 is used as a work area or temporary data storage area for the MPU 221. The MPU 221 controls the carriage drive system 223, the transport drive system 224, the recovery drive system 225, and the head drive system 226 via an ASIC (Application Specific Integrated Circuit) 222. Further, the MPU 221 is configured to be able to read / write from / to the print buffer 229 and the mask buffer 230 readable / writable from the ASIC 222.

  The print buffer 229 temporarily stores binary recording data converted into a format that can be transferred to the recording head 5. When performing multi-pass printing, the mask buffer 230 temporarily holds a mask pattern used for AND (logical product) as needed for data transferred from the print buffer 229 when transferring to the print head 5. A plurality of sets of mask patterns for multi-pass printing with different numbers of passes are prepared in the ROM 227, and the corresponding mask patterns are read from the ROM 227 and stored in the mask buffer 230 during actual printing. Of course, the AND processing with the mask pattern in the mask buffer 229 is not performed when it is not necessary as in the case of one-pass printing. When the recording data sent from the host apparatus 200 is in the index format, index development is performed using a dot arrangement pattern described later with reference to FIG. 4 to obtain binary recording data, which is stored in the print buffer 229.

  The recording operation is started when the recording data is sent from the host device 200 to the reception buffer 250 of the printer control unit 220 in the inkjet recording apparatus 200. The printer control unit 220 analyzes the recording data received from the host device 200 and generates information necessary for recording such as recording data, recording quality, and margin information. At this time, recording data, recording quality, media, margin information, and the like are processed by the MPU 221 via the ASIC 222 and held in the RAM 228. This information is referred to later if necessary, and is used for separation of processes.

  The final binary recording data obtained as described above is written in the print buffer 229 in a state where it can be transferred to each recording head 5. When the recording data held in the print buffer 229 has accumulated to an amount capable of recording actual band data, the MPU 221 transports the recording medium by the transport driving system 224 via the ASIC 222, and the carriage driving system 223. To move the carriage 1. Further, the recovery system is driven by the recovery drive system 225 to perform a necessary recovery operation before the recording operation. Further, the image output position and the like are set in the ASIC 222, and the carriage 1 is driven to start the recording operation. When the carriage 1 moves and reaches the recording start position set in the ASIC 222, the recording data is sequentially read from the print buffer 229 in accordance with the ejection timing. Under the control of the head driving system 226, the recording head 5 is driven and ejected according to the transferred data. The recording operation is realized by repeating the processing from the reception of the image from the host device 200 to the steps so far.

  FIG. 3 is a diagram illustrating data processing in the host device 200 and the printer main body 240 described above. In the host device 200, the printer driver 210 generates 600 × 600 dpi R, G, B (red, green, blue) multi-value data (here, 8 bits each). Next, color conversion processing 500 from R, G, B to R ′, G ′, B ′ data is performed in order to obtain a color space that matches the printer 240. Next, color separation processing 510 is performed for converting R′G′B ′ 8-bit data into 8-bit data of K, LC, LM, C, M, and Y, which is data of each ink color used in the printer. . The resolution of the data obtained by this remains 600 × 600 dpi.

  Subsequently, quantization processing 520 is performed on 8-bit (255 gradation) data of K, LC, LM, C, M, and Y to obtain recording data of 4 bits (5 gradations) for each color. As the quantization processing 520, a known error diffusion method or dither method can be used. Information necessary for recording such as recording quality, media, and margin information is added to the quantized 4-bit (5-tone) data of K, LC, LM, C, M, and Y, and then transferred to the printer main body 240. . In the printer main body, index expansion processing 530 is performed on the received 4-bit data of each color to obtain final binary data having a resolution of 1200 dpi.

  FIG. 4 is a diagram for explaining index expansion. In the present embodiment, the printer main body 240 indexes data of pixel units represented by 4 bits (5 gradations) of 600 dpi into 1 bit (binary) data of 1200 dpi. Accordingly, the developed matrix size is 2 (horizontal) × 2 (vertical). As shown in FIG. 4, patterns (800, 801, 803, 804) developed in advance for 4-bit data (“0000”, “0001”, “0010”, “0011”, “0100”) for five gradations. Is set. Therefore, each pixel is recorded with any one of 0 to 4 dots. These dot arrangement patterns may be stored in advance in the ROM in the recording apparatus main body, or may be downloaded from the host apparatus together with the recording data. The five gradation data is sent from the printer driver 210 of the host device, and the printer main body develops 600 dpi 4-bit data on a pixel-by-pixel basis on the basis of each gradation level pattern set above, and 1200 dpi one bit (second floor). Key) data is generated. By ejecting ink from the recording head based on this 1-bit (2 gradation) data, dots corresponding to the image to be recorded are formed on the recording medium.

  Next, a configuration for dot-counting data for one band will be described with reference to FIG. FIG. 5 is a diagram schematically showing a dot count area of data for one band recorded by the recording head 5. In the recording medium, an area that can be recorded by one scan of the recording head can be defined as a band, and when this band is recorded, the number of ejections from each recording head corresponding to the recording data is counted as a dot. As shown in FIG. 5, one band has a length in the sub-scanning direction corresponding to the range of 1280 ejection ports of the recording head 5, and this length is the 600 dpi resolution of the index data described above. That is 640 pixels. One band is divided (101, 102, 103,...) In units of vertical (sub-scanning direction) 640 pixels × horizontal (main scanning direction) 640 pixels. The area divided in this way becomes a dot count area, dot count is performed for each dot count area, and the next band is similarly divided in units of 640 × 640 pixels (201,...). Dot dot count. In the example shown in FIG. 5, the length of one band in the sub-scanning direction is the same as the length of the recording head in the ejection port array direction, but this length is not the same as the length in the nozzle array direction. May be. Further, although the area in the main scanning direction is 640 pixels in the example shown in FIG. 5, this area can also be determined according to the temperature rise characteristics of the recording head.

  Next, a method of calculating the threshold dot number, which will be described later with reference to FIG. 10, will be described with reference to FIG. FIG. 6 is a diagram showing the threshold dot number set for the detected print head temperature (hereinafter referred to as the head temperature). As shown in FIG. 6, up to a head temperature of 20 ° C., the maximum count dot number 1638400 in one dot count area is set as the threshold dot number. In the present embodiment, dot count is performed on the index data described above. Therefore, one pixel of this data is one in which 0 to 4 dots are arranged in a 2 × 2 matrix as described in FIG. That is, a maximum of 4 dots are arranged for each pixel of the index data. Accordingly, the maximum number of dots in the dot count area of 640 pixels × 640 pixels is 640 × 640 × 4 = 1638400.

  Next, a threshold value is determined by a linear function shown below from a head temperature of 20 ° C. to 60 ° C.

Y = −40960 × X + 2457600 (where Y is the threshold dot number and X is the head temperature)
In this embodiment, the threshold dot number is set by a linear function, but it may be set by a one-dimensional LUT or calculation by a function.

  Next, a configuration for comparing the threshold dot number and the dot count value for each dot count area will be described with reference to FIG. FIG. 7 is a diagram schematically showing a configuration for comparing the threshold dot number and the dot count value. As shown in FIG. 7, areas (1006 to 1011) having the largest number of dots are detected in the dot count areas 1000 to 1005 in one band for the recording data of the recording heads of the respective ink colors. As an example, the maximum number of dots for K, LC, and C (1006 to 1008) is 1400000 dots, and the maximum number of dots for LM, M, and Y (1009 to 1011) is 200000 dots, respectively.

  On the other hand, head temperatures 1018 to 1023 for each ink color immediately before the start of scanning are acquired. And the threshold dot number with respect to each head temperature 1018-1023 is calculated based on the relationship shown in FIG. As an example, the K head temperature 1018, the LC head temperature 1019, and the C head temperature 1020 are each 30 ° C., and the LM head temperature, the M head temperature, and the Y head temperature are each 40 ° C. As a result, the threshold dot numbers (1012 to 1014) of K, LC, and C are −40960 × 30 + 2457600 = 1228800. Further, the threshold dot numbers (1015 to 1017) of LM, M, and Y are −40960 × 40 + 2457600 = 819200.

  In the above example, when the maximum number of dots of each color is compared with the threshold number of dots, the maximum number of dots 1400000 exceeds the threshold number of dots 12228800 for K, LC, and C. On the other hand, for LM, M, and Y, the maximum number of dots 200000 does not exceed the threshold number of dots 819200. That is, there are colors that exceed the threshold number of dots.

  In this case, in this embodiment, as will be described later with reference to FIG. 10, when printing a continuous image including a dot count area exceeding the threshold number of dots, the carriage speed (scanning speed of the printhead) and the drive of the printhead are driven. Change the frequency (discharge frequency). Specifically, recording is performed at a reduced carriage speed and drive frequency. Thereby, the temperature rise of the recording head can be suppressed. Note that the dot recording density (resolution) can be prevented from changing before and after the carriage speed is changed by lowering the drive frequency in accordance with the speed change when the carriage speed is reduced.

  As described above, in the present embodiment, the carriage speed and the driving frequency are changed in recording in units of continuous images including a dot count area exceeding the threshold dot number. As a result, continuous images can be recorded without being affected by the carriage speed change based on the dot count. Here, the continuous image refers to an image in a region where images are continuous, that is, an image in a region where recording is not performed and the background of the recording medium forms a certain region and is not separated by the background region.

  FIG. 8 is a diagram showing a continuous image formed by a plurality of bands, and shows an example in which the continuous image 100 is formed by four dot count regions in each of the first to third scans (scanning). In the example shown in FIG. 8, it is assumed that the dot count value exceeds the threshold value in any dot count area of the second band corresponding to the second scan, and for example, the carriage speed is changed only in the band including that area. In this case, the density differs between the first band image of the first scan and the third band image of the third scan before and after that, and density unevenness may occur in the entire continuous image. Therefore, in this embodiment, when a continuous image is recorded, if the dot count value exceeds a threshold value in any of the dot count areas included in the image, the carriage speed is switched in units of the continuous image.

  FIG. 9 is a block diagram illustrating a configuration related to the carriage speed switching process of the present embodiment, and FIG. 10 is a flowchart illustrating the carriage speed switching process of the present embodiment. The configuration shown in FIG. 9 is mainly realized by the configuration of the control system of the inkjet printer 240 of the present embodiment shown in FIG.

  In FIG. 9, the head temperature detection unit 901 detects the head temperature based on the output of the temperature sensor attached to the recording head 5 and outputs a detection signal. That is, the head temperature detection unit 901 according to this embodiment includes a temperature sensor for temperature detection, and an A / D conversion circuit that converts an analog signal output from the temperature sensor into a digital signal. The corresponding digital signal is output. As described above, the dot count unit 902 counts the number of dots to be formed in each area (dot count area) obtained by dividing the band representing the area on the recording medium to be recorded in one scan as described above. To do. Based on the head temperature detected by the head temperature detection unit 901 and the count value for each divided area in the dot count unit, the determination unit 903 determines the maximum number of dots and the threshold number of dots described later with reference to FIG. Make a comparative decision.

  The drive frequency determination unit 904 determines the drive frequency and carriage speed of the recording head 5 based on the determination result of the determination 903. The determined drive frequency is notified to the head drive system 226, the carriage speed is notified to the carriage drive system 223, and the transport amount of the paper is notified to the transport drive system 224, and recording control is performed.

  The processing executed by each unit shown in FIG. 9 will be described with reference to the flowchart of FIG. In this embodiment, the recording resolution of the recording head 5 in the scanning direction is 1200 dpi, the carriage speed is 16.7 inches / sec, and the driving frequency of the recording head 5 is 1200 × 16.7 = 20 KHz.

  First, the head temperature of each color recording head is acquired by the head temperature detection unit 901 (S101). Next, the dot count unit 902 sets a dot count for each divided area obtained by dividing an area corresponding to one band recorded by the recording head 5 in units of a predetermined monitor size (in this case, 640 × 640 pixels). Done. This dot count is performed independently for each color (S102). Since this divided area is a unit for performing dot count, the divided area is also referred to as “dot count area” below.

  The counted number of dots is notified to the determination unit 903, and a value corresponding to the maximum number of dots is calculated for each color among the number of dots counted in each divided area in one band by the determination unit 903 (S103). ). Information on the acquired head temperature is notified to the determination unit 903, and the determination unit 903 calculates the threshold dot number of each color from the head temperature of each color (S104). Further, the determination unit 903 compares the maximum number of dots corresponding to each color with the threshold number of dots corresponding to each color, and determines whether the maximum number of dots exceeds the threshold number of dots for any one color. (S105). The determination unit 903 includes means for predicting the head temperature after scanning from the head temperature information before starting scanning and the number of dots of each color.

  If the determination unit 903 determines that the threshold dot count has been exceeded, flag information (for example, flag value “1”) indicating that is stored (S106). Next, it is determined whether the bands are still continuous (S107). If there is continuous data, the above S102 to S107 are repeated. That is, the above processing is repeated until processing of all the bands included in one continuous image is completed. If it is determined in step S107 that there is no continuous print data, the flag information is referred to (S108), and it is determined whether there is a divided area exceeding the threshold dot number in the band of the continuous print data.

  When there is no divided area exceeding the threshold in the continuous image, flag information (for example, flag value “0”) indicating that fact is notified from the determination unit 903 to the drive frequency determination unit 904, and the drive frequency determination unit 904 A predetermined drive frequency and carriage speed are maintained (S109). On the other hand, when there is a divided area exceeding the threshold in the continuous image, flag information (for example, flag value “1”) indicating that fact is notified from the determination unit 903 to the drive frequency determination unit 904. As a result, the drive frequency determination unit 904 changes the drive frequency of the recording head 5 to 14.4 KHz and the carriage speed to 12 inches / sec. That is, the drive frequency and the carriage speed are reduced (S110). Then, recording is performed with the driving frequency and carriage speed determined by the driving frequency determination unit 904 (S111).

  As described above, the dot count and the processing up to the determination of the carriage speed and the driving frequency based on the dot count are repeated in units of continuous images, so that the low speed region and the high speed region are not mixed in the continuous image, and the recorded image The density unevenness can be suppressed.

(Second Embodiment)
The second embodiment of the present invention relates to a carriage speed switching process when different continuous images are recorded by the same scan. FIG. 11 is a diagram illustrating an example in which different continuous images are recorded by the same scanning. In the example shown in FIG. 11, a part of the continuous image 1100 and another continuous image 1101 is recorded by the first scan of the recording head 5.

  In FIG. 11, in the first scan, a part of the continuous image 1100 and part of the continuous image 1101 are recorded. Therefore, the upper part 101 to 104 of the band recorded by the scan and the lower part 101a to 104a that are not continuous are separately Dot count can be performed. Therefore, in this embodiment, in FIG. 11, for example, when it is determined that the upper part 101 to 104 is the low-speed recording, and the lower part 101a to 104a and another band area 201 to 204 are the high-speed recording, as shown in FIG. The upper and lower recording data of the first scan are recorded in a second scan, which is a separate scan. At the same time, areas 201 to 204 of other bands are recorded by the third scan. Thus, the carriage speed can be switched in units of continuous images, and density unevenness due to the difference in carriage speed can be suppressed.

  The configuration relating to the carriage speed switching process of the present embodiment is obtained by adding a data allocation determination unit 905 to the configuration shown in FIG. 9 referred to in the first embodiment. In FIG. 9, when the continuous image is less than the length of the print head in the sub-scanning direction as in the continuous image 1100 of FIG. 11, the dot count unit 902 determines the area of that length as a divided area, The dot count of each color is performed for each divided region of size. The data allocation determination unit 905 determines the recording data allocation of the recording head 5 based on the determination result of the determination unit. The determined drive frequency and recording data allocation are notified to the head drive system 226, the carriage speed is notified to the carriage drive system 223, and the transport amount of the paper is notified to the transport drive system 224, and recording control is performed.

  FIG. 13 is a flowchart showing the carriage speed switching process with the above configuration. Also in this embodiment, the recording resolution of the recording head 5 in the scanning direction is 1200 dpi, the carriage speed is 16.7 inches / sec, and the driving frequency of the recording head 5 is 1200 × 16.7 = 20 KHz.

  The process of this embodiment is different from the process shown in FIG. 10 according to the first embodiment in the process of step S112. That is, in step S112, the data allocation determination unit 905 performs data allocation so that the continuous image 1100 (areas 101 to 104) is recorded in the first scan in the example illustrated in FIG. Further, data allocation is performed so that a partial area (101a to 104a) of the continuous image 1101 is recorded by the second scan and the continuous image 1101 is recorded by the first scan.

  If the dot count value of the area exceeds the threshold dot number for each area to which the scan times are assigned as described above by the drive frequency determining unit 904, the drive frequency of the recording head 5 is set to 14.4 KHz, The carriage speed is changed to 12 inch / sec. That is, processing for reducing the driving frequency and the carriage speed is performed (S110). Then, recording is performed based on the recording data allocation determined by the drive frequency determination unit 904 and the data allocation determination unit 905, the drive frequency, and the carriage speed (S111).

  By repeating the above processing in units of continuous images of print data, low speed areas and high speed areas are not mixed in continuous print data, so density unevenness due to changes in carriage speed can be suppressed.

(Third embodiment)
As shown in FIG. 12 according to the second embodiment, in addition to dividing the scan to be recorded into a place where one band is recorded by different scans, the recording medium is transported as shown in FIG. You may make it record using all the ejection openings of a recording head by a scan. Thereby, in the case of recording data as shown in FIG. 15, the number of scans can be reduced. As a result, density unevenness can be suppressed and throughput can be increased by reducing the number of scans.

(Fourth embodiment)
In the first to third embodiments described above, the case where the present invention is applied to one-pass printing has been described. However, the present invention can also be applied to multi-pass printing. In this case, the dot count for each dot count area is a number in which the unit area recording is completed by N scans, and in the case of N pass recording, the number of counted dots is 1 / N. The carriage speed is switched in units of continuous images.

(Fifth embodiment)
In the first to fourth embodiments described above, the head temperature is detected by the head temperature detection unit, and the threshold dot number is obtained from the result and the number of dots to be recorded. The threshold dot number is calculated in advance. Alternatively, it may be held on the ROM of the recording apparatus main body.

(Other embodiments)
In each of the above-described embodiments, the area for counting dots is an area obtained by dividing the band corresponding to the area to be recorded in one scan. However, this count area may be the band itself for one scan. .

Another object of the present invention is to supply a storage medium storing a program code for realizing the functions of the above-described embodiments to a system or apparatus, and the computer of the system or apparatus reads and executes the program code stored in the storage medium. Is also achieved.
That is, a recording system for supplying the program code for realizing the functions of the above-described embodiment to a computer to which various devices including the recording apparatus are connected, and operating the various devices by the program code stored therein is also included in the present invention. Included in the range.

DESCRIPTION OF SYMBOLS 1 Carriage 2 Recording head 200 Host apparatus 220 Printer control part 221 MPU
222 ASIC
227 ROM
228 RAM
229 Print buffer 240 Inkjet recording apparatus

Claims (4)

An inkjet recording apparatus that performs recording by scanning a recording head that ejects ink with respect to a recording medium,
Dot counting means for counting the number of dots to be recorded by the scanning based on the recording data in an area on the recording medium to be recorded by one scanning of the recording head;
Determining means for determining for each region on the recording medium to be recorded by one scan of the recording head whether or not the number of dots counted by the dot counting means is greater than a predetermined threshold;
According to the determination result of the determination means, for each continuous image in which the image indicated by the recording data is a continuous image on the recording medium, the scanning speed of the recording head and the ejection frequency of the recording head for recording the continuous image are determined. A decision means to
An ink jet recording apparatus comprising:   When recording a plurality of continuous images in an area on a recording medium to be recorded by one scan of the recording head, the recording head further includes a control unit that records the plurality of continuous images by different scans. The ink jet recording apparatus according to claim 1.   The inkjet control apparatus according to claim 2, wherein the control unit further changes a range of ejection ports used by the recording head in at least one of different scans in which the plurality of continuous images are recorded. An inkjet recording method for performing recording by scanning a recording head for discharging ink on a recording medium,
A dot counting step of counting the number of dots to be recorded by the scanning based on the recording data in an area on the recording medium to be recorded by one scanning of the recording head;
A determination step of determining, for each region on the recording medium to be recorded by one scan of the recording head, whether or not the number of dots counted in the dot counting step is greater than a predetermined threshold;
In accordance with the determination result in the determination step, for each continuous image in which the image indicated by the recording data is an image continuous on the recording medium, the scanning speed of the recording head and the discharge frequency of the recording head for recording the continuous image are set. A decision process to decide;
An inkjet recording method characterized by comprising:

Images