Recording apparatus, control method, and program

Abstract

To determines a recording condition on the basis of a temperature under an installation environment of a recording device.SOLUTION: A control method comprises the steps of: obtaining temperature under an installation environment of a recording device; setting a threshold based on the obtained temperature; and setting a scanning speed in scanning means and the number of split printing times in accordance with the obtained temperature, by comparing the set threshold with a value determined by counting the number of times of driving a recording element.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to an image processing apparatus, an image processing method, a recording apparatus, and a program for recording an image on a recording medium.

Background Art

[0002] As a recording head used in a recording apparatus, a so-called inkjet recording head that forms dots on a recording medium by ejecting ink droplets to record an image is known. In a recording apparatus equipped with an inkjet recording head, ink is supplied from an ink tank through a supply channel, and an image is recorded by controlling the recording head based on image data specified by a user.

[0003] Depending on the image data sent from a host computer, the density of the dots to be recorded may not be uniform, and the power required to drive the recording elements for ejecting ink droplets may vary depending on the area. If one tries to always ensure a certain productivity without considering such power fluctuations, it is necessary to cope with the case where the dot density to be recorded is maximum. As a result, it is necessary to provide a large-capacity power supply and a circuit that can withstand the input and output of the large-capacity power supply. In addition, in order to meet the demand for higher recording speed, the recording elements provided in the recording head have become denser and longer. Along with this, there is a problem that the power consumed by the recording head is increasing.

[0004] Patent Document 1 describes a configuration in which the number of driving times of recording elements in an area where an image is to be recorded is measured, and when the number of driving times is greater than a predetermined threshold value, the carriage equipped with the recording head is decelerated, or the recording of the area is divided into a plurality of scans. In this way, by analyzing the recording data before the recording operation, it is possible to suppress the power consumed by the recording head, make the most of the constant power capacity of the apparatus, and suppress a decrease in throughput.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 2005-224955 Summary of the Invention Problems to be Solved by the Invention

[0006] However, in the technology described in Patent Document 1, the temperature in the installation environment of the recording device is not considered. An object of the present invention is to determine recording conditions based on the temperature in the installation environment of the recording device. Means for Solving the Problems

[0007] The present invention is a recording device that records an image by applying ink droplets onto a recording medium, and includes an acquisition means for acquiring the Environment temperature in the installation environment of the recording device, a recording head including a plurality of recording elements driven by applying electrical energy, and a scanning means for relatively scanning the recording head and the recording medium , previous calculation means for calculating values related to driving of the plurality of recording elements for applying ink droplets to a predetermined area in one relative scan based on an instruction for recording, and the Based on the environmental temperature determination means for determining recording conditions for recording an image based on a threshold value and the values related to driving calculated by the calculation means, and control means for controlling the recording head and the scanning means based on the recording conditions determined by the determination means. , the calculating means further calculates a second value related to driving of the plurality of recording elements for applying ink droplets to a second area having a size smaller than the predetermined area, and the determining means further determines the recording conditions based on a threshold value corresponding to the environmental temperature and corresponding to the second area and the second value related to the driving It is characterized by comprising. Advantages of the Invention

[0008] According to the present invention, recording conditions can be determined based on the temperature in the installation environment of the recording device. Brief Description of the Drawings

[0009]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0010] (First Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] <Overall Schematic of the Apparatus> Fig. 1(a) is an external view of an inkjet recording apparatus (hereinafter also referred to as an image recording apparatus) according to the present embodiment. The inkjet recording apparatus of the present embodiment is a so-called serial scan type image recording apparatus, and scans (scans) a carriage on which a recording head is mounted in a Y direction intersecting the X direction in which a recording medium P is conveyed. By driving a recording element provided in the recording head 9 during this scan, ink droplets are applied, and an image is recorded on the recording medium P. In the figure, the X direction is the direction in which the recording medium P is conveyed, the Y direction is the direction in which the carriage scans, and the Z direction is the direction intersecting the X direction and the Y direction, respectively.

[0012] Using Fig. 1, the configuration of the image recording apparatus and the outline of the operation during recording will be described. First, starting from the state where the recording medium P is held by the spool 6, a paper feed roller is driven via a gear by a paper feed motor (not shown), and the recording medium P is fed and conveyed to a position where the recording head 9 can record. On the other hand, at a predetermined conveyance position, a carriage unit 2 on which the recording head 9 is mounted is scanned along a guide shaft 29 extending in the Y direction of the figure by a carriage motor (not shown). Note that the recording head 9 is detachably mounted on the carriage unit 2. Then, during one scan, the recording element provided in the recording head 9 is driven at a timing based on a position signal obtained by the encoder 7. By driving this recording element, ink droplets are ejected from the ejection port (nozzle) and land on the recording medium P. In one scan of the recording head 9, an image can be recorded on an area corresponding to the array range of the recording elements provided in the recording head 9. The recording width corresponding to the array range of this recording element is called the band width. In the present embodiment, the scan speed of the carriage unit 2 is 40 inches per second, and the recording resolution is 1200 dots per inch, that is, 1200 dpi (dots / inch).

[0013] After one scan, the recording medium P is conveyed by a predetermined amount in the X direction. Thereafter, in the next scan, an image is recorded on the area corresponding to the next band width. Note that the image recording apparatus may convey the band width, that is, the array range of the recording elements, between each scan, or may convey the recording medium P after multiple scans without conveying it for each scan. Further, in n scans, ink may be applied based on the decimated data, and the conveyance of a width of 1 / n band is repeated between each scan, so that an image may be completed by using different recording elements for recording on the same area (so-called multi-pass recording).

[0014] Specifically, as will be described later with reference to FIG. 1(b), a plurality of recording elements for ejecting ink are arranged in the X direction in the figure on the recording head 9 of the present embodiment. A flexible wiring board 1 for supplying a signal pulse for driving each recording element, a signal for head temperature control, etc. is attached to the recording head 9, and the other end of the flexible wiring board 1 is connected to a control circuit that executes control of the image recording apparatus.

[0015] A carriage belt can be used to transmit the driving force from the carriage motor to the carriage unit 2. Instead of the carriage belt, for example, other driving methods such as a lead screw that is rotationally driven by a carriage motor and extends in the main scanning direction, and an engaging portion provided on the carriage unit 2 that engages with the groove of the lead screw can also be used.

[0016] The recording medium P fed and conveyed is sandwiched and conveyed between a paper feed roller and a pinch roller, and is guided to the recording position on the platen 4, that is, the main scanning area of the recording head 9. Note that in the standby state, since the face surface of the recording head 9 is capped, the cap is opened prior to recording to make the recording head 9 or the carriage unit 2 in a scanable state. Then, when the recording data for one scan is accumulated in the buffer, the carriage unit 2 is scanned by the carriage motor 3, and an image is recorded on the recording medium P as described above.

[0017] In this figure, the environmental temperature and humidity sensor 8 is indicated by a dashed line. Generally, the environmental temperature and humidity sensor 8 is arranged at a position away from members that serve as vibration sources or heat sources such as motors and heaters in order to eliminate errors and measurement noise. Originally, it is provided at a position that is difficult to view, such as the back side of the apparatus, but in this specification, for the sake of explanation, it is described in a form that is transparent.

[0018] Figure 1(b) is a schematic diagram showing the operation of the recording medium P and the recording head in a serial scan type recording apparatus, and is a view of the recording head 9 and the recording medium P as seen from above. Using this figure, the operation of the serial recording method will be described. By driving the carriage motor 3, the recording head 9 mounted on the carriage unit 2 reciprocally scans in the width direction (Y direction) orthogonal to the conveyance direction (X direction) of the recording medium P. As described above, in an image recording apparatus using the serial recording method, multi-pass recording can be performed in which recording elements that eject ink droplets are made different for the same area by relative scanning between the recording head 9 and the recording medium P. By this multi-pass recording, density unevenness due to variations in the recording characteristics of each recording element can be suppressed.

[0019] <Recording head configuration> Figure 2 is a schematic diagram for explaining the configuration of the recording head 9. Figure 2(a) is a schematic perspective view shown from the direction in which ink is ejected. Figure 2(b) is an enlarged view of the portion of the recording element substrate on the left side of Figure 2(a), and Figure 2(c) is a schematic perspective view showing the connection portion between the apparatus and the head on the back surface of Figure 2(a).

[0020] In FIG. 2(a), two recording element substrates 10 are juxtaposed on the recording head 9. On one recording element substrate, a plurality of recording element rows 11 to 14 capable of ejecting inks of black (Bk), gray (Gy), light gray (Lgy), and light cyan (Lc) are arranged. On the other recording element substrate, a plurality of recording element rows 15 to 18 capable of ejecting inks of cyan (C), light magenta (Lm), magenta (M), and yellow (Y) are arranged. For each recording element row, ink is supplied from an ink common liquid chamber 24, which will be described later, through an ink flow path inside the recording head 9.

[0021] FIG. 2(b) is a plan view showing the detailed configuration of the recording element substrate 10. It is the recording element substrate on which the recording element rows 11 to 14 are arranged among the two recording element substrates juxtaposed on the recording head 9. In the present embodiment, two rows of recording element rows are provided for each ink color. Each recording element row is provided with 256 recording elements at a pitch of 600 dpi in the X direction. Further, a total of 512 recording elements of each color are arranged in a state shifted by a half pitch, that is, 1200 dpi, with respect to the opposing recording element rows. And each recording element is formed with a discharge port, and ink droplets are discharged from the discharge port by driving the recording element. Also, at the ends of the recording element substrate 10 in the X direction, temperature sensors S6, S7, S8, and S9, which are diode sensors, are arranged, and the temperature of the recording element substrate 10 can be detected. The temperature sensors S6 to S9 are located at a position about 0.2 mm away from the outermost discharge port position of the recording element row in the sub-scanning direction and at the intermediate position between the two recording element rows in the Y direction. In the central portion of the recording element row in the X direction, temperature sensors S1, S2, S3, S4, and S5 formed of diodes for detecting the temperature of the central portion of the recording element row are formed, and these are also arranged at the intermediate position sandwiched between the two recording element rows.

[0022] The sub-heaters 19 and 20 for keeping the recording head 9 warm are formed so as to surround the recording element substrate 10, and are located 1.2 mm outside from the outermost recording element row in the Y direction and 0.2 mm outside from the temperature sensor 53 in the X direction.

[0023] Using FIG. 2(c), the connection between the recording head 9 and the main body will be described. The recording head and the main body device are electrically connected through the flexible substrate wiring 1 of FIG. 1 via the contact pad 21. Electric signals for controlling the ejection and heat retention of ink droplets, as well as the power consumed by the recording head, are supplied to the recording head via the contact pad. At the time of connection, a receiving mechanism such as a pin may be prepared on the main body side as a fixed part, and the recording head may be pressed against the main body device and fixed to achieve a stable connection configuration. Also, the power supply for supplying the power used for the ejection operation and the power supply for supplying the power used for heat retention may have individual pin wirings or may be a common wiring. If the voltage values used for ejection and heat retention are the same, the number of terminals can be reduced by making the pin wirings common. Also, even when the voltages are different, they can be made common by providing a constant voltage output electronic circuit on the recording head side. Note that the wiring configuration of the electrical connection is not limited to the above.

[0024] FIG. 3 is a cross-sectional view taken along line A-A′ of FIG. 2(b). In this figure, 27 is a support substrate, 22 is a recording element, and 23 is an ejection port. Also, an ink flow path 24 as a flow path is formed between the support substrate 27 and the orifice plate 28, and a partition wall (not shown) is provided between the plurality of flow paths 24. The recording element 22 of this embodiment is an electrothermal conversion element that converts electrical energy into thermal energy and generates heat. The recording element 22 is provided on the support substrate 27 so as to face the ink ejection port 23, and a protective film or the like is formed on the surface of the recording element 22. Then, ink is supplied to each flow path 24 via a common liquid chamber 26 that communicates with each flow path 24 from below in FIG. 3.

[0025] <Configuration example of control system> FIG. 4 is a diagram showing an example of a control circuit of an image recording apparatus. A programmable peripheral interface (hereinafter referred to as PPI) 101 receives a command signal (command) sent from a host computer 100 and a recording information signal including recording data, and transfers it to an MPU 102. At the same time, status information of the image recording apparatus is sent to the host computer 100 as necessary. Also, data input / output is performed between a console 106 having a setting input unit for the user to perform various settings on the image recording apparatus and a display unit for displaying a message to the user. Further, it receives signals from a sensor group 107 including a home position sensor for detecting that the carriage unit 2 to the recording head 9 is in the home position, a capping sensor, and the like.

[0026] An MPU (microprocessing unit) 102 controls each part in the image recording apparatus according to a control program stored in a control ROM 105. A RAM 103 stores the received signal, is used as a work area of the MPU 102, and temporarily stores various data. A print buffer 121 stores the recording data developed in the RAM 103 and the like, and is a memory area having a capacity for recording a plurality of lines. In addition to the above control program, the control ROM 105 can store fixed data corresponding to data used in the control process described later (for example, data for determining a combination of temperature sensors related to the main part of the present embodiment). These parts are controlled by the MPU 102 via an address bus 117 and a data bus 118.

[0027] Motor drivers 114, 115, and 116 are motor drivers for driving a capping motor 113, a carriage motor 3, and a paper feed motor 5 according to the control of the MPU 102, respectively.

[0028] The sheet sensor 109 detects the presence or absence of a recording medium, that is, whether the recording medium has been supplied to a position where recording by the recording head 9 is possible. The driver 111 is a driver for driving the recording elements of the recording head 9 in accordance with the recording information signal. The environmental temperature and humidity sensor 8 detects the environmental temperature and environmental humidity in the installation environment of the recording apparatus main body as described above. As long as the configuration can detect the ambient temperature of the apparatus, the location where the environmental temperature and humidity sensor 8 is disposed is not limited.

[0029] The power supply unit 120 is a power supply unit that supplies power to each of the above units, and includes an AC adapter and a battery as a driving power supply device. Note that the power supply unit 120 of the present embodiment plays both a role of supplying power for discharging ink droplets from the recording elements of the recording head 9 and a role of supplying power to the sub-heater for heat preservation.

[0030] In a recording system including an image recording apparatus and a host computer 100, when transmitting recording data from the host computer 100 via a parallel port, an infrared port, a network, or the like, required commands are added to the head portion thereof. Examples of such commands include the type of recording medium on which recording is to be performed, the medium size, the recording quality, and the presence or absence of automatic discrimination of objects. Examples of the type of recording medium include plain paper, OHP sheets, glossy paper, and further, special recording medium types such as transfer films, cardboard, and banner paper. The medium size includes A0 size, A1 size, A2 size, B0 size, B1 size, B2 size, and the like. The recording quality includes draft, high quality, medium quality, emphasis on specific colors, and the type of monochrome / color. Further, when a configuration for applying a processing liquid for improving the ink fixing property on the recording medium is adopted, information determining the presence or absence of the application is transmitted as a command.

[0031] Following these commands, on the image recording apparatus side, data necessary for recording is read from the ROM 105, and recording is performed based on that data. Examples of data necessary for recording include data for determining the number of recording paths (number of scans) during the above-described multi-pass recording, the amount of ink injection per unit area of the recording medium, and the recording direction. Also, there are the mask types for data decimation applied during multi-pass recording and the driving conditions (e.g., the shape and application time of the driving pulse applied to the heating part) based on the detected values of the temperature sensors in the recording head 9. Furthermore, there may be data such as the dot size, the conditions for transporting the recording medium, the number of colors used, and even the carriage speed.

[0032] <Power consumption due to differences in environmental temperature> Next, the power consumption due to differences in environmental temperature, which is an issue in this embodiment, will be described. Here, two conditions of environmental temperatures of 28°C and 13°C will be compared and described in detail.

[0033] FIG. 5 is a diagram showing the power consumption of the heat-insulating heater (sub-heater) and the recording element when recording an image such as a poster that uses a large amount of ink. In both cases, it is the power supplied from the power supply unit 120. From the left, it shows the power consumption of the heat-insulating heater, the power consumption used for ejecting ink droplets in the recording element, and the total power consumption of the heat-insulating heater and the recording element. FIG. 5(a) shows the power consumption when the environmental temperature is 28°C, and FIG. 5(b) shows the power consumption when the environmental temperature is 13°C. In the figure, the amount indicated by the broken line is the power that can be used as the recording head.

[0034] Assuming the target temperature of the recording head is 40°C, in the case of an environmental temperature of 28°C in FIG. 5(a), heating for a difference of 12°C is required, and in the case of an environmental temperature of 13°C in FIG. 5(b), heating for a difference of 27°C is required. That is, when the environmental temperature is 13°C, more than twice the power is required to reach the target temperature compared to the case where the environmental temperature is 28°C.

[0035] On the one hand, the available power shown by the broken line is determined by the device configuration and is constant, not changing with the ambient temperature. Therefore, the amount of power that can be used for ejecting ink droplets in the recording element is the amount obtained by subtracting the amount of power used by the heat-insulating heater from the available power shown by the broken line.

[0036] As described above, when the ambient temperature is different, the greater the difference from the target temperature, the smaller the amount of power that can be used in the recording element, and the smaller the difference from the target temperature, the greater the amount of power that can be used in the recording element. In actual recording, the amount of power used in the recording element varies depending on the recording data, but it is necessary to control the conditions of the recording operation so that it falls within the range of the amount of power that can be used in the recording element. For example, reducing the carriage speed, reducing the area to be recorded in one carriage scan, etc. When setting the amount of power that can be used in the recording element without considering the ambient temperature, it is necessary to determine the recording conditions according to the case where the ambient temperature is the lowest. In that case, for example, when the ambient temperature is 28 °C, the power consumption of the heat-insulating heater is small, and although power can be supplied to the recording element, strict recording conditions are set without using the power indicated by the arrow in the figure, and the throughput may decrease. In contrast, in the present embodiment, based on the ambient temperature, the amount of power used in the heat-insulating heater is taken into account, and control is performed so that the amount of power that can be used in the recording element can be used without remainder. As a result, a decrease in throughput can be suppressed. In addition, in the present embodiment, in addition to such a configuration, the number of times the recording element is driven is calculated for each scan, and the carriage operation speed and the number of multi-passes are changed according to the number of times the recording element is driven.

[0037] FIG. 6 is a flowchart for explaining each step of the recording control of the present embodiment. The control of this flowchart is executed by the 102 MPU executing the program stored in the ROM 105.

[0038] First, in step S601, an instruction to record from the user is received. Here, it is assumed that the paper type is "plain paper" and the recording quality is "standard" as the recording conditions, and the processing flow will be described.

[0039] In step S602, the user's recording instruction is analyzed to obtain recording mode information. Here, FIG. 7(a) shows a recording mode table, and FIG. 7(b) shows a threshold ratio parameter table according to the environmental temperature. FIG. 7(b) will be described in detail later.

[0040] In the recording mode table shown in FIG. 7(a), based on the paper type and recording quality selected by the user, the details of the control content of the apparatus are defined. For example, information such as the number of pass divisions, carriage speed, and threshold value of the recording element drive times (hereinafter referred to as HDth) is described. The recording mode is an internal parameter that defines detailed control when recording. In recent image recording apparatuses, in order to accommodate the individual preferences of users, various information such as image processing resolution, error diffusion type, and ink type used is defined in various formats and set as recording conditions.

[0041] In step S603, a threshold value HDth corresponding to the recording mode obtained in step S602 is obtained. Here, it is assumed that the recording condition set by the user is plain paper and standard mode, and a value of "115200" is obtained as the threshold value HDth.

[0042] Here, the threshold value HDth will be described. The image recording apparatus of the present embodiment assumes a device configuration where the number of recording elements is 512 nozzles per color, the number of ink colors is 4 colors of CMYK, the maximum possible recording width in the scanning direction (Y direction) is 10 inches, and the driving resolution of the recording elements is 600 dpi. In such a printer, the maximum value of the number of times the recording elements are driven within one scan (hereinafter referred to as HDnum) is 512 nozzles per color × 10 inches × 600 dpi = 307,200 times. However, due to restrictions such as the allowable current amount of the power supply configuration and electrical terminals of the device, the current amount that can actually be passed as the ejection current to the recording head is defined as the threshold value HDth. The threshold value HDth is set to a value corresponding to the moving speed (carriage speed) of the carriage unit 2 equipped with the recording head 9. This is because the average current amount per unit time becomes a load on the electric circuit. When a plurality of recording modes with different carriage speeds can be set, even if the number of dots ejected onto the recording medium P is the same, the number of times the recording elements are driven per unit time differs according to the carriage speed. Therefore, the threshold value HDth is determined based on the number of times the recording elements are driven per unit time, and for the same driving frequency, the value of HDth is set to be smaller when the carriage speed is faster and larger when the carriage speed is slower. The present embodiment is control aimed at suppressing an excessive load on such electrical elements and electric circuits.

[0043] In step S604, temperature information indicating the environmental temperature at the start of recording is acquired. Here, a high-temperature environment is assumed, and the room temperature is set to 28°C. In the present embodiment, the configuration is such that the environmental temperature is acquired at the timing when the recording job is received in step S601. Note that a situation where the environmental temperature changes during the recording operation can be considered, such as when the recording time is very long or when the room temperature rises from a low temperature environment by warming the room using air conditioning. In such a case, although the order is different from that of the present embodiment, the environmental temperature may be acquired for each scan, and the timing for acquiring the environmental temperature is not limited to the above configuration.

[0044] In step S605, based on the ambient temperature obtained in step S604, a threshold ratio HDthRatio is acquired according to the threshold ratio parameter table corresponding to the ambient temperature shown in FIG. 7(b). In the threshold ratio parameter table corresponding to the ambient temperature, it is set such that the higher the ambient temperature, the higher the threshold ratio HDthRatio which is a weighting coefficient. This is because the higher the ambient temperature, the smaller the amount of power required to keep warm using the sub-heater, and thus the amount of power available for ejection from the recording head 9 can be increased. Here, according to the ambient temperature of 28 degrees obtained in step S604, 1.2 is acquired as the threshold ratio HDthRatio.

[0045] In step S606, a drive count threshold HDth_env corresponding to the ambient temperature is calculated. The drive count threshold HDth_env is calculated by multiplying the threshold HDth corresponding to the recording mode acquired in step S603 and the threshold ratio HDthRatio acquired in step S605.

[0046] In step S607, temperature control is started. For the temperature control, the sub-heater provided in the recording head 9 shown in FIG. 2 is used, and heating is performed until the temperature sensors S6 to S9 reach the target value. In this embodiment, it is assumed that the heating control (heat retention control) is continued so that the target temperature can be kept while there is recording data even after the target temperature is reached. Here, the case where the target temperature is constant is described, but a form in which the target temperature is changed according to the ink color, ambient temperature, etc. may also be possible.

[0047] This embodiment has a configuration in which a plurality of temperature sensors are provided for one recording head. However, for the head temperature used for determination, for example, the average temperature, the maximum temperature, a weighted one, etc. of the plurality of temperature sensors can be considered. Here, the average value of the temperatures acquired by the plurality of temperature sensors is used as the head temperature, but it is not limited to this. For example, when recording an image in monochrome mode, it can be appropriately changed, such as using a weighting coefficient with a larger ratio of the temperature sensors existing near the recording element array of the black ink.

[0048] Here, the temperature control necessary for stable ejection will be described. If no ink droplets are ejected from the recording element during one scan, moisture evaporates from the droplets on the ejection port surface, and the ink viscosity locally increases. Due to this thickening of the ink, it becomes difficult to eject ink droplets, or the landing positions of the ejected ink droplets shift. On the other hand, the viscosity of the ink can be decreased by controlling the heating or heat retention of the recording head. Therefore, temperature control is performed to heat the recording head to the target temperature before the start of scanning. The target temperature at this time is set to a temperature at which stable ejection can be obtained also at the timing when one scan is completed. This target temperature can be appropriately set according to the head configuration and ink physical properties, and in this embodiment, it is set to 40°C.

[0049] In step S608, the recording data for the next scan is developed in the print buffer 121. In the print buffer 121, the recording data is developed in a band-shaped memory area corresponding to a vertical size of 512, which is the number of recording elements, and a horizontal size of 6000 corresponding to the image recording possible width of 10 inches in the Y direction × 600 dpi for each ink color. That is, the recording data corresponding to the number of ink colors is developed.

[0050] Here, a method for converting from general input data, RGB image data, to recording data corresponding to each ink color will be described. Here, a form using four colors of CMYK inks will be described.

[0051] FIG. 8 is a flowchart showing the image processing in the image recording apparatus of the present embodiment. In step S801, an RGB original image signal obtained by an image input device such as a digital camera or a scanner, or by computer processing, is converted into an R'G'B' signal by color processing A. In the present embodiment, the input resolution of the multi-value image data is 600 dpi × 600 dpi, and the luminance data (R, G, B) represented by 8-bit 256 gradations for each pixel. The color processing A is a process of converting the original image signal RGB into an image signal R'G'B' adapted to the color reproduction range of the recording apparatus.

[0052] In step S802, the R’G’B’ signal is converted by the color processing unit B into signals corresponding to respective color inks. Here, for each pixel of 600 dpi×600 dpi resolution of the multi-value output data of each ink color, it is converted into data expressed in 12-bit 4096 gradations. Here, the converted signals are density signals C1, M1, Y1, and K1 corresponding to cyan, magenta, yellow, and black colors respectively. In this color processing B, the output values are obtained using a three-dimensional look-up table (3D LUT) for R, G, B inputs and C, M, Y, K outputs. For input values outside the grid points, interpolation operations are performed using the output values of the surrounding grid points.

[0053] In step S803, gamma correction is performed on the density signals C1, M1, Y1, and K1 using a correction table to obtain C2, M2, Y2, and K2. Here, it is converted from 12-bit data of each color at 600 dpi×600 dpi resolution into 8-bit 256 gradation data.

[0054] Through the image processing flow of steps S801 to S803 as described above, recording data corresponding to each ink color is generated.

[0055] Returning to FIG. 6, in step S609, the data of the print buffer developed in step S608 is analyzed, and the drive count HDnum of the recording element is counted. In this embodiment, the value obtained by summing the drive counts for the four CMYK colors is treated as the drive count HDnum.

[0056] In step S610, the drive count HDnum calculated in step S609 is compared with the drive count threshold HDth_env obtained in step S606, and it is determined whether it is equal to or greater than the drive count threshold HDth_env. If it is determined that it is equal to or greater than the drive count threshold HDth_env, the process proceeds to step S611. If it is determined that it is less than the drive count threshold HDth_env, the process proceeds to step S613.

[0057] In step S611, a recording method is determined. Since the number of driving times HDnum is equal to or greater than the driving times threshold HDth_env, it is necessary to reduce the power consumption per unit time. FIG. 9 is a table for setting the recording method. In the setting table shown in FIG. 9, recording methods corresponding to recording modes such as paper type and recording quality are set. The recording method set here is a recording method with lower power consumption per unit time compared to the recording method executed when proceeding to step S613, that is, when the number of driving times is less than the driving times threshold.

[0058] The threshold ratio DownTh1 indicates the ratio to the driving times threshold HDth_env. The driving times threshold HDth_env is multiplied by the threshold ratio, and the multiplication value is compared with the number of driving times HDnum. In this embodiment, a plurality of values are used as the threshold ratio for comparison. Thereby, the approximate ratio of the number of driving times HDnum to the driving times threshold HDth_env can be estimated, and an appropriate recording method can be determined.

[0059] FIG. 10 is a flowchart showing the process of determining the recording method using the threshold ratio. In step S1001, the information of the recording mode acquired in step S602 is acquired. In step S1002, based on the acquired recording mode, the values of the threshold ratio DownTh1 for condition 1 and the threshold ratio DownTh2 for condition 2 are acquired from the table in FIG. 9.

[0060] In step S1003, a multiplication value of the driving times threshold HDth_env and the value of the threshold ratio DownTh1 for condition 1 is calculated, and it is determined whether the value of the number of driving times HDnum is greater than this multiplication value. For example, the value of the threshold ratio DownTh1 in the plain paper / standard mode is 2. Therefore, in this determination, it is determined whether the value of the number of driving times HDnum is greater than twice the driving times threshold HDth_env. If Yes, that is, if it is greater than twice, proceed to step S1004; if No, that is, if it is twice or less, proceed to step S1005.

[0061] In step S1004, a recording method corresponding to condition 1 is obtained from the table in FIG. 9. In step S1003, since it is determined that the value of the number of driving times HDnum is greater than twice the driving time threshold HDth_env (condition 1), the recording method needs to reduce the power consumption per unit time to less than half compared to the case where it is less than the threshold. Therefore, a recording method is set in which the carriage speed during scanning is 0.6 times the standard speed, and the recording data for the next scan is recorded in two parts.

[0062] Here, with reference to FIG. 11, the method of recording in two parts will be described. In this figure, the horizontal direction is the scanning direction (Y direction) of the recording head 9, and the vertical direction is the direction in which the recording elements are arranged (X direction). Here, an image recorded in one scan is shown, and the length in the vertical direction corresponds to the length that the recording head 9 can record in one scan, that is, the width in which the recording elements are arranged. In this figure, only one column of the recording element array of the recording head is shown.

[0063] FIG. 11(a) shows the case of recording without division, and shows an image recorded in one scan using all the recording elements arranged in the recording head. FIG. 11(b) shows an image recorded in two parts in two scans. The 512 recording elements arranged in the recording head 9 are divided into the upper half and the lower half, and in the first scan, the recording is performed using the 1st to 256th recording elements in the upper half, and in the second scan, the recording is performed using the 257th to 512th recording elements in the lower half. In this way, by limiting the number of recording elements that eject ink droplets in one scan, the amount of power consumed per unit time in the recording head 9 can be suppressed. As the method of division, a method of thinning out the recording data using a mask pattern or the like may be used.

[0064] Returning to Fig. 10, if the condition 1 is not met in step S1003, that is, when it is determined that the value of the drive count HDnum is less than twice the drive count threshold HDth_env, the process proceeds to step S1005. In step S1005, the multiplication value of the drive count threshold HDth_env and the threshold ratio DownTh2 of condition 2 is calculated, and it is determined whether the value of the drive count HDnum is greater than this multiplication value. The value of the threshold ratio DownTh2 in the plain paper / standard mode is 1.5. Therefore, in this determination, it is determined whether the value of the drive count HDnum is greater than 1.5 times the drive count threshold HDth_env. If it is greater, the process proceeds to step S1006; if it is smaller, the process proceeds to step S1007.

[0065] In step S1006, from the table in Fig. 9, the recording method corresponding to condition 2 is obtained. In step 1005, since it has been determined that the value of the drive count HDnum is greater than 1.5 times and less than twice the drive count threshold HDth_env (condition 2), the recording method needs to reduce the power consumption per unit time to 2 / 3 or less compared to the case when it is less than the threshold. Therefore, the recording method with the carriage speed during scanning being 0.6 times the standard speed is set.

[0066] If it does not meet either condition 1 or condition 2, the process proceeds to step S1007 to obtain the recording method of condition 3. In step S1005, since it has been determined that the value of the drive count HDnum is greater than the drive count threshold HDth_env and less than 1.5 times (condition 3), the recording method with the carriage speed during scanning being 0.8 times is set.

[0067] In this way, in step S611, the recording conditions are set according to the ratio of the drive count HDnum to the drive count threshold HDth_env. At this time, when the drive count HDnum is greater than the drive count threshold HDth_env, the recording conditions with a lower power consumption per unit time are set compared to the case when it is less than the drive count threshold HDth_env. Thereby, the image can be recorded within the predetermined power consumption range.

[0068] Furthermore, the setting method of the recording method is not limited to the setting method of the present embodiment. For example, by calculating the ratio of the value of the number of driving times HDnum to the reference value and changing the carriage speed based on the reciprocal thereof, the power consumption can be suppressed. Also, the number of divisions of the recording data may be increased to three or four. Further, a form in which condition 2 is not defined, such as the clean mode of plain paper, may be used. In this case, without performing the determination branch in step S1005, the process proceeds to step S1007 to set the recording method.

[0069] Returning to FIG. 6, in step S612, the data in the print buffer is regenerated. When the recording method of divided recording is set in step S611, recording data corresponding to the divided recording is generated in the print buffer. In the present embodiment, the number of divisions = 2, and as described with reference to FIG. 11, the data for one scan is divided into two to generate recording data for two scans.

[0070] In step S613, an image is recorded on the recording medium based on the recording data on the print buffer. When the data divided in step S612 is regenerated, the image is recorded in N scans based on the recording data for N scans corresponding to the number of divisions N. Also, when it is set to change the carriage speed in the recording method set in step S611, the carriage unit 2 is controlled based on the set recording conditions.

[0071] In step S614, it is determined whether the recording has ended. If the recording has not ended and there is still recording data remaining, the process returns to step S608 to generate from the recording data for one scan and continue the recording process.

[0072] Through the above processing, it is possible to set the amount of electric power per unit time that can be used for ink ejection by the recording head according to the environmental temperature. With such a configuration, it is possible to efficiently distribute the electric power used to keep the recording head warm by the sub-heater and the electric power used for ink ejection by the recording head, contribute to improving usability while suppressing throughput reduction.

[0073] In addition, the control of this embodiment is particularly effective when the power supply that supplies power to the recording element and the power supply that supplies power to the sub-heater are treated as one power supply capacity. This is because in electrical components such as the substrate, wiring, and power supply, control is required to suppress the instantaneous applied current amount and the average applied current amount below a predetermined threshold value. On the other hand, even when the power supply for the recording element and the power supply for the sub-heater have different configurations, there may be a case where suppression of the amount of electric power is required in terms of the maximum amount of electric power during normal operation of the image recording apparatus. Even in such a case, it is possible to apply the configuration of this embodiment. For example, a form without a sub-heater for keeping the recording head warm may be used. The temperature keeping control of the recording head can also be performed by applying pulses to the recording element, which is an electrothermal conversion element, to such an extent that ink droplets are not ejected, in addition to the case of using a sub-heater. Even in such a form, since the premise that the amount of electric power that can be used for keeping the recording head warm varies depending on the environmental temperature is the same, the same effect can be obtained by applying the above configuration of this embodiment.

[0074] In addition, in the recording head of this embodiment, although the sub-heater is arranged so as to surround the outer periphery of the recording element substrate 10, it is not limited to such a form, and various layouts such as wiring along the recording element array can be considered.

[0075] Also, in the present embodiment, the threshold ratio HDhRatio described in the threshold ratio parameter table according to the environmental temperature in FIG. 7(b) is changed only according to the environmental temperature regardless of the recording mode, but it may be changed in consideration of other factors. For example, since the carriage speeds in a plurality of recording modes are not the same, the threshold ratio HDhRatio may be set in consideration of the carriage speed set for each recording mode. Further, since the types and numbers of inks used may vary depending on the recording mode, such as in monochrome mode or color mode, the threshold ratio parameter table may be extended to have one for each recording mode, and the value for each recording mode to be used may be used.

[0076] Furthermore, in recent image recording apparatuses, apparatuses having an ink circulation mechanism or even apparatuses provided with an ink temperature control device can be considered. In such apparatuses, the ink temperature flowing into the recording head may be acquired and used as the environmental temperature for determination. Also, when the recording operation has not been performed for a certain period of time or more, the temperature of the recording head 9 is considered to be substantially equal to the temperature in the installation environment of the recording apparatus. Therefore, under such conditions, the temperatures acquired by the temperature sensors S6 to S9 may be used as the environmental temperature in the present embodiment. In this case, it is preferable to continue using the temperature acquired before the start of the recording operation as the environmental temperature instead of acquiring the environmental temperature for each scan.

[0077] Also, in step S609 of FIG. 6 in the present embodiment, the drive count HDnum of the recording element is counted based on 256 - gradation multi - value data, but it is not limited to this form. By quantizing the 256 - gradation multi - value data, quantization data indicating the actual ejection or non - ejection of ink from the recording element is generated, and the drive count HDnum may be counted based on this quantization data. Also, it is not limited to the form of counting the drive count of the recording element, and it may be a form of acquiring a dot count value and comparing it with a threshold value, or a form of comparing a value obtained from data indicating the amount applied for each ink color with a threshold value.

[0078] Furthermore, the present invention is not limited to a serial recording type recording apparatus such as the image recording apparatus of the present embodiment, and is applicable to a so-called full multi-type image recording apparatus in which a recording medium is conveyed with respect to a fixed recording head. In the case of the full multi-type, the form of the ink colors may be plural with respect to one recording head, or the form may be such that a recording head is provided for each ink color. Also, in the present embodiment, although the number of driving times of the recording element per scan is counted to determine the recording method, for example, in the case of cut paper, the number of driving times of the recording element may be counted based on the page unit, and in the case of roll paper, based on the division of a predetermined unit, and the recording method may be determined. In a full multi-type image processing apparatus, by reducing the conveyance speed of the recording medium, the power consumption per unit time can be suppressed.

[0079] Also, in the present embodiment, in addition to the amount of power used for discharging the ink, as the necessary power, the amount of power used for keeping the recording head warm has been described, but a configuration that takes into account the power for other configurations may also be used. In recent years, in order to support multiple uses, in the case of an image recording apparatus provided with a fixing mechanism, similar to the sub-heater for keeping warm, parameters such as HD_Ratio may be set in consideration of the amount of power of the fixing mechanism. Also, in such a product form, an apparatus capable of setting the fixing temperature during the fixing period is common. In order to correspond to such uses, an HD_Ratio that takes into account the set temperature during the fixing period can be set.

[0080] (Second Embodiment) In the above-described embodiment, control for suppressing the power consumption per unit time by split recording and reducing the carriage speed is adopted based on the total value of the number of driving times of the recording element for one scan. On the other hand, depending on the type of recording element, it may be necessary to consider an instantaneous current for a time shorter than the amount of power for the time taken for one scan. In such a case, not only the total value of the number of driving times of the recording data for one scan, but also the area of one scan is further divided into narrower areas, and control of the amount of power per unit time is required based on the number of driving times of each area. In the present embodiment, drive control considering the instantaneous current in a divided area smaller than the one scan area will be described.

[0081] Figure 12 is a flowchart for explaining each step of the recording control of the present embodiment. Regarding the points overlapping with the steps in FIG. 6 of the first embodiment, the description will be omitted.

[0082] Since the processes of step S1201 and step S1202 are the same as those of step S601 and step S602, the description will be omitted.

[0083] In step S1203, the drive count threshold HDth corresponding to the recording mode acquired in step S1202 and the drive count threshold HDth_narrow in a small divided area are acquired. FIG. 13(a) is a table in which the drive count threshold HDth corresponding to each recording mode is set, similar to FIG. 7(a), and further, the value of the threshold HDth_narrow used for comparison with the drive count in the divided area is added. Since FIG. 13(b) is the same as FIG. 7(b), the description will be omitted. Here, the case where the plain paper / standard mode is set will be described as an example. As the drive count threshold corresponding to the plain paper / standard mode, the threshold for one scan HDth = 115200 and the threshold for the divided area HDth_narrow = 57600 are acquired.

[0084] Since step S1204 and step S1205 are the same processes as step S605 and step S605, the description will be omitted.

[0085] In step S1206, two values, the drive count threshold HDth_env corresponding to the environmental temperature and the threshold HDth_env_narrow for the divided area, are calculated. The calculation method is the same as that in step S606, and HDthRatio is multiplied by HDth and HDth_narrow respectively.

[0086] Since step S1207 to step S1209 are the same processes as step S607 to step S609, the description will be omitted.

[0087] In step S1210, the number of driving times of the recording elements in the divided area is counted. In step S1209, the number of driving times of the recording elements was counted based on the recording data for one scan. Here, however, the number of driving times of the recording elements is counted for each divided area, and the maximum value of the count is set as the number of driving times HDnum_narrow in the divided area.

[0088] FIG. 14 is an image diagram showing a print buffer for one scan of a certain ink color. In the present embodiment, the number of recording elements A is 512 nozzles, and the scan width B is a memory area of 10 inches × 600 dpi = 6000. FIG. 14(a) shows the entire one scan, FIG. 14(b) shows the counting of the number of driving times in the first divided area, and FIG. 14(c) shows the counting of the number of driving times in the second divided area. The width of the divided area in the recording element array direction is 512 nozzles, which is the same as the area of one scan.

[0089] In step S1209, first, the number of driving times in the area for one scan shown in FIG. 14(a) is counted. Next, the number of driving times in the divided area marked by the broken line in FIG. 14(b) is counted. Next, the number of driving times in the divided area marked by the broken line in FIG. 14(c) is counted. As shown in FIGS. 14(b) and (c), the divided area counted for the first time and the divided area counted for the second time are set so that a part thereof overlaps. In this way, the number of driving times is counted while shifting the divided area, and the maximum value in a certain one scan area is calculated. This maximum value is determined as the number of driving times HDnum_narrow in the divided area. Here, the print buffer for one color is described, but actually, the print buffers for CMYK four colors may be developed simultaneously, and HDnum_narrow may be determined by the total value for the four colors. When totaling the four colors, even if it is the same pixel on the recording medium, since the recording element arrays are physically shifted, the ejection timings are not the same in the absolute time axis, and a slight shift occurs. Considering this shift, for example, it is possible to realize a more preferable form by obtaining the total value in consideration of the amount of shift in the ejection timing based on the distance between the recording element arrays.

[0090] In step S1211, it is determined whether the number of driving times is equal to or greater than a threshold value. Specifically, it is determined whether the number of driving times HDnum in one scan area is equal to or greater than the driving time threshold value HDth_env in one scan area, and whether the number of driving times HDnum_narrow in the divided area is equal to or greater than the driving time threshold value HDth_env_narrow in the divided area. If it is determined that the number of driving times is equal to or greater than the threshold value, the process proceeds to step S1212. If it is determined that the number of driving times is smaller than the threshold value, the process proceeds to step S1214.

[0091] In step S1212, a recording method is determined. This determination method is the same as that for step S611. The process in step S611 is similarly performed for the number of driving times HDnum_narrow in the divided area. When the conditions of the recording methods determined by the number of driving times HDnum in one scan and the number of driving times HDnum_narrow in the divided area are different, the one with the smaller condition number may be selected. For example, when the recording method obtained by HDnum is condition 2 and the recording method obtained by HDnum_narrow is condition 1, the recording method of condition 1 is selected.

[0092] Thereafter, the processes from step S1213 to step S1215 are the same as the processes from step S612 to step S614, and thus the description thereof is omitted.

[0093] In this way, even for a divided area smaller than one scan area, by counting the number of driving times of the recording element and comparing it with the threshold value, it is possible to suppress a decrease in throughput even when using an electric element with weak withstand voltage performance in an instantaneously short time.

[0094] In the present embodiment, a configuration in which the same recording method is selected for one scan area and the divided area has been described, but they do not have to be the same. A form in which the recording methods are set individually may also be used. Further, in the above embodiment, the recording method was determined by comparing with a threshold value for each of the one scan area and the divided area, but a form in which the recording method is determined only by comparison for the divided area may also be used. Further, the size of the divided area is not limited to the above example, and the width in the X direction may be shorter than the width of one scan.

Explanation of Signs

[0095] 9 Recording head 10 Recording element substrate 19 Sub-heater 20 Sub-heater 22 Recording element

Claims

1. A recording apparatus that records an image by applying ink droplets onto a recording medium, an acquisition means for acquiring the environmental temperature in the installation environment of the recording apparatus, a recording head including a plurality of recording elements that are driven by applying electric energy, a scanning means for relatively scanning the recording head and the recording medium, a calculation means for calculating a value related to driving of the plurality of recording elements for applying ink droplets to a predetermined area in one relative scan based on the instruction of the recording, a determination means for determining recording conditions for recording an image based on a threshold value based on the environmental temperature and the value related to the driving calculated by the calculation means, a control means for controlling the recording head and the scanning means based on the recording conditions determined by the determination means, comprising the calculation means further calculates a second value related to driving of the plurality of recording elements for applying ink droplets to a second area having a size smaller than the predetermined area, the determination means further determines the recording conditions based on a threshold value corresponding to the environmental temperature and corresponding to the second area and the second value related to the driving, the recording apparatus being characterized in that.

2. The determination means determines based on a first threshold value when the environmental temperature is a first temperature, and determines based on a second threshold value greater than the first threshold value when the environmental temperature is a second temperature higher than the first temperature, the recording apparatus according to claim 1, characterized in that.

3. The determining means determines: (i) when the value related to the driving is smaller than the threshold value, a first recording condition in which the amount of electric power that can be used per unit time for discharging ink droplets from the plurality of recording elements is a first amount; and (ii) when the value related to the driving is larger than the threshold value, a second recording condition in which the amount of electric power that can be used per unit time for discharging ink droplets from the plurality of recording elements is a second amount smaller than the first amount. The recording apparatus according to claim 1 or 2, characterized by this.

4. The recording apparatus according to claim 3, characterized in that the relative scanning speed in the second recording condition is slower than the relative scanning speed in the first recording condition.

5. The recording apparatus according to claim 3 or 4, characterized in that the number of relative scans for applying ink droplets to the predetermined area in the second recording condition is larger than the number of relative scans for applying ink droplets to the predetermined area in the first recording condition.

6. The recording apparatus according to any one of claims 1 to 5, characterized in that the value related to the driving calculated by the calculating means is the number of driving times for driving the plurality of recording elements.

7. The recording apparatus according to any one of claims 1 to 5, characterized in that the value related to the driving calculated by the calculating means is a dot count value.

8. The recording apparatus according to any one of claims 1 to 5, characterized in that the value related to the driving calculated by the calculating means is a value obtained from data indicating the application amount for each ink color.

9. The recording apparatus according to any one of claims 1 to 8, further comprising a heater for heating the recording head.

10. The recording apparatus according to claim 9, characterized in that a power source for supplying power to the plurality of recording elements and a power source for supplying power to the heater have a common configuration.

11. The determination means determines based on a third threshold value greater than the second threshold value when the environmental temperature is a third temperature higher than the second temperature. The recording apparatus according to claim 2.

12. The recording head includes a plurality of recording element arrays corresponding to inks of a plurality of colors. A value related to driving calculated by the calculation means is a total value of the inks of the plurality of colors. The recording apparatus according to any one of claims 1 to 5.

13. The plurality of recording elements are arranged in a first direction, and relative scanning by the scanning means is performed in a second direction intersecting the first direction. The recording apparatus according to any one of claims 1 to 12.

14. Further includes a conveying means for conveying the recording medium in the first direction. The scanning means scans the recording head in the second direction. The recording apparatus according to claim 13.

15. A control method for a recording apparatus including a recording head including a plurality of recording elements driven by applying electric energy, and a scanning means for relatively scanning the recording head and the recording medium, and recording an image by applying ink droplets onto the recording medium, comprising: An acquisition step of acquiring an environmental temperature in an installation environment of the recording apparatus; A calculation step of calculating a value related to driving of the plurality of recording elements to apply ink droplets to a predetermined area in one relative scan based on the instruction of the recording; A determination step of determining recording conditions for recording an image based on a threshold value based on the environmental temperature and the calculated value related to driving; A control step of controlling the recording head and the scanning means based on the determined recording conditions; Comprising In the calculation step, a second value related to driving of the plurality of recording elements for applying ink droplets to a second area having a size smaller than the predetermined area is further calculated. In the determination step, the recording conditions are determined based on a threshold value corresponding to the environmental temperature and corresponding to the second area, and further based on the second value related to the driving.

16. A program for causing a computer to execute each step described in the control method of claim 15.

Images