Recording device and program

Abstract

To provide a technique which is advantageous in relatively easily achieving both productivity improvement and quality improvement of recording.SOLUTION: A recording device with a plurality of nozzles comprises: a plurality of heating elements which is arrayed in correspondence with the plurality of nozzles, and which respectively heats ink and causes the ink to be discharged from a corresponding nozzle; a plurality of temperature detecting elements provided in correspondence with the plurality of heating elements; inspection means for inspecting a discharge mode of ink from the nozzles based on signals from the plurality of temperature detecting elements; and signal generating means. The recording device includes as operation modes: a recording mode in which recording is performed by the plurality of heating elements without conducting inspection by the inspection means; and an inspection mode in which inspection is conducted by the inspection means based on recording performed by the plurality of heating elements. The signal generating means periodically generates a column signal, and periodically generates a latch signal for driving a drive object among the plurality of heating elements with respect to a column cycle. In the inspection mode, a cycle for generating the latch signal is longer than in the recording mode.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates primarily to a recording device. [Background technology]

[0002] Among recording devices such as inkjet printers, some perform ejection inspections by evaluating the manner in which ink is ejected from the nozzles in order to improve the quality of recording (see Patent Document 1). According to Patent Document 1, a heating element and a temperature detection element are provided corresponding to the nozzle, and the ejection inspection is performed based on the result of the first-order differentiation of the signal waveform of the temperature detection element when the heating element is driven. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-000914 A Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, it is possible to improve recording productivity (production efficiency of printed matter) by shortening the interval between the timings at which each heating element is driven. However, it takes a certain amount of time to perform the ejection inspection described in Patent Document 1 for each nozzle. There is a demand for a technology that can relatively easily achieve both improved recording productivity and improved recording quality.

[0005] The present invention was made in response to the inventor's recognition of the above-mentioned problems, and an exemplary object of the present invention is to provide a technology that is advantageous for relatively easily achieving both improvement in recording productivity and improvement in recording quality. [Means for solving the problem]

[0006] One aspect of the present invention relates to a recording device, the recording device comprising: A recording device having a plurality of nozzles for performing recording by ejecting ink, a plurality of heating elements arranged corresponding to the plurality of nozzles, each of which heats ink to cause the ink to be ejected from a corresponding nozzle; A plurality of temperature detection elements provided corresponding to the plurality of heating elements; an inspection means for inspecting the state of ink ejection from the nozzles based on signals from the plurality of temperature detection elements; and a signal generating means for generating a signal for driving the plurality of heating elements, a recording mode in which recording is performed by the plurality of heating elements without performing an inspection by the inspection means, and an inspection mode in which inspection is performed by the inspection means based on the recording performed by the plurality of heating elements, The signal generating means periodically generates a column signal that defines a period during which each of the heating elements can be driven, and periodically generates a latch signal for driving a target of the heating elements among the heating elements for a column period that is one period of the column signal, and sets a period for generating the latch signal longer in the inspection mode than in the recording mode. It is characterized by: Effect of the Invention

[0007] According to the present invention, it is possible to improve the printing productivity and the printing quality. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view showing an example of a portion of the internal structure of a recording apparatus. [Diagram 2] FIG. 2 is a system block diagram illustrating a control system of the printing apparatus. [Diagram 3] FIG. 2 is a schematic diagram showing an example of the structure of an element substrate. [Figure 4] FIG. 13 is a diagram showing an example of a system configuration for explaining a method for processing a temperature detection result. [Diagram 5] FIG. 4 is a diagram showing an output result from a temperature detection element. [Figure 6] FIG. 2 is a diagram showing an example of the configuration of a circuit section capable of implementing time-division driving. [Figure 7] 5 is a diagram for explaining the timing of input of a latch signal; [Figure 8] 4 is a flowchart showing the drive control of the recording apparatus. [Figure 9] 5 is a diagram for explaining the timing of input of a latch signal; [Figure 10] 5 is a diagram for explaining the timing of input of a latch signal; [Figure 11] 4 is a flowchart showing the drive control of the recording apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] <Example of recording device configuration> 1 shows an example of a portion of the internal structure of a recording device 1000 according to an embodiment. In this embodiment, the recording device 1000 includes a recording head 3 capable of performing recording at once across the entire width of a recording medium 2. Such a recording head 3 may also be expressed as a line head, a full line head, or the like.

[0011] The recording device 1000 further includes a transport unit 1 that transports the recording medium 2 in a predetermined direction, and the recording head 3 extends in a direction intersecting (substantially perpendicular to) the transport direction of the recording medium 2. The transport unit 1 includes two transport rollers 81 and 82 that are arranged at a distance F apart in the transport direction of the recording medium 2, and transports the recording medium 2 by rotating them.

[0012] The recording head 3 has a plurality of nozzles (ejection ports) arranged in the extension direction, and can eject ink (or liquid) from each nozzle. The recording head 3 is an inkjet type head that ejects ink using thermal energy, and has a plurality of recording elements built in corresponding to the plurality of nozzles. In this example, each recording element is an electrothermal conversion element (also called a heating element, heater, etc.), and when a pulse voltage based on a recording signal is applied to a corresponding switch element, it is energized to heat the ink, thereby ejecting the ink from the corresponding nozzle.

[0013] The recording head 3 is provided with a negative pressure control unit 230 that controls the pressure (negative pressure) in the ink path, a liquid supply unit 220 that communicates with the negative pressure control unit 230, and a liquid connection part 111 that serves as an ink supply port / discharge port for the liquid supply unit 220. The negative pressure control unit 230, the liquid supply unit 220, and the liquid connection part 111 can be housed and fixed in a predetermined housing 80.

[0014] In such a configuration, the print head 3 performs printing on the print medium 2 that is continuously or intermittently conveyed by the conveyance section 1. Such a printing apparatus 1000 can also be expressed as a line-type printing apparatus.

[0015] The recording head 3 is configured to support color printing and is capable of ejecting cyan (C), magenta (M), yellow (Y) and black (K) inks. The liquid supply unit 220 forms supply paths capable of supplying each type of ink to the recording head 3, and the recording head 3 is connected to an ink tank via the supply paths. In addition, the recording head 3 is electrically connected to an electrical control unit (not shown) for supplying signals (recording signals) for controlling the ejection of ink and supplying power from a power source.

[0016] The recording device 1000 is not limited to the above-mentioned line type recording device, and other known configurations may be adopted. For example, the recording device 1000 may be a serial type recording device that records on the recording medium 2 while reciprocating / scanning the recording head 3 by a carriage in a direction intersecting the transport direction of the recording medium 2. Such a recording head 3 may also be expressed as a serial head, etc.

[0017] The recording medium 2 is typically a paper material, but may be other sheet-like materials. The recording medium 2 may be a cut sheet cut to a predetermined size, or a roll sheet formed by winding up a long sheet.

[0018] <Example of a recording device system configuration> 2 is a system block diagram for explaining a control system of the recording device 1000. The recording device 1000 further includes a controller unit 410 and a print engine unit 417. In this embodiment, the recording device 1000 is a multifunction peripheral (MFP) that further includes a scan function, and further includes a scanner engine unit 411.

[0019] The controller unit 410 can include a main controller 401, a host IF 402, a wireless IF 403, an operation panel 404, a print engine IF 405, a RAM 406, a ROM 407, an image processing unit 408, and a scanner engine IF 409. In this specification, IF refers to an interface for realizing the exchange of signals with external elements (input / output or transmission / reception).

[0020] The main controller 401 performs predetermined arithmetic processing based on an operation input on an operation panel 404 and / or based on a print job input from the host device 400 via a host IF 402 or a wireless IF 403. For example, the main controller 401 executes a target program using a RAM 406 and a ROM 407, and performs image processing on image data included in the print job using an image processing unit 408.

[0021] A touch panel display or the like is typically used for the operation panel 404, which accepts operation input from the user and displays necessary information to the user. Instead of the operation panel 404, an operation input unit that accepts operation input and a display unit that displays necessary information may be provided separately, that is, the operation input unit and the display unit may be provided integrally or separately.

[0022] The input of a print job from the host device 400 to the recording device 1000 may be realized via wireless communication or wired communication, or may be realized by reading from an external storage device connected to the recording device 1000. A known communication method may be used for wireless communication or wired communication. For example, examples of communication methods using wireless communication include Wi-Fi (Wireless Fidelity (registered trademark)) and Bluetooth (registered trademark). Also, examples of communication methods using wired communication include USB (Universal Serial Bus).

[0023] The print engine IF 405 exchanges signals with the print engine unit 417. The scanner engine IF 409 exchanges signals with the scanner engine unit 411.

[0024] In this manner, the controller unit 410 performs drive control for the entire system of the printing apparatus 1000.

[0025] The print engine unit 417 may include a controller IF 418, a print controller 419, a ROM (Read Only Memory) 420, and a RAM (Random Access Memory) 421. The print engine unit 417 may further include an image processing controller 422, a maintenance control unit 423, an ink supply control unit 424, a head carriage control unit 425, a transport control unit 426, and a head IF 427.

[0026] The controller IF 418 exchanges signals with the controller unit 410. The print controller 419 executes a target program using the ROM 420 and RAM 421, thereby performing signal processing required for executing recording. For example, image data and commands based on a print job received via the controller IF 418 are stored in the RAM 421. Based on instructions from the print controller 419, the image processing controller 422 converts the image data into recording data so that the recording head 3 can handle the image data, and stores the converted data in the RAM 421.

[0027] The maintenance control unit 423 can control the maintenance operation of the recording head 3, and controls the driving of a cap unit and a wiping unit, which are maintenance units not shown. The ink supply control unit 424 controls the driving of the liquid supply unit 220 so that the pressure of the ink supplied to the recording head 3 is within a reference range. The head carriage control unit 425 can change the orientation and position of the recording head 3 depending on the operating state (e.g., recording state, maintenance state, etc.) of the recording device 1000. The transport control unit 426 controls the transport of the recording medium 2 by controlling the driving of the transport rollers 81 and 82. The head IF 427 exchanges signals with the recording head 3.

[0028] In this manner, the print engine unit 417 controls the driving of the printing section including the print head 3 .

[0029] The scanner engine unit 411 may include a RAM 412, a transport control unit 413, a controller IF 414, a scanner controller 415, and a sensor 416. When executing a scan function, the scanner controller 415 causes the transport control unit 413 to scan a target document (a sheet member on which an image is formed) with the sensor 416, thereby acquiring image data and storing it in the RAM 412. A known optical sensor such as a CCD / CMOS image sensor may typically be used as the sensor 416. The controller IF 414 exchanges signals with the controller unit 410.

[0030] In this way, the scanner engine unit 411 controls the driving of a scanner section (not shown), and the controller unit 410 is also capable of outputting the acquired image data to the print engine unit 417 .

[0031] The controllers 401, 415 and / or 419 are CPUs (central processing units) that perform calculations to control the drive of the corresponding elements, and may be MPUs (microprocessor units) with accompanying memory, or simply processors, etc.

[0032] <Configuration of element substrate having recording elements> As shown in Figures 3(a) to 3(c), the print head 3 includes an element substrate 5 on which a plurality of printing elements 309 corresponding to a plurality of nozzles are formed. Figure 3(a) shows a schematic plan view of the vicinity of the printing elements, Figure 3(b) shows a schematic cross-sectional view of the element substrate 5 taken along the cutting plane x-x', and Figure 3(c) shows a schematic cross-sectional view of the element substrate 5 taken along the cutting plane y-y'. The element substrate 5 may be referred to as a printing element substrate, etc.

[0033] As can be seen from FIGS. 3(a) to 3(c), the element substrate 5 has a multilayer wiring structure formed by stacking a plurality of layers 302 to 311. In this example, a wiring 303 is formed on an insulating film 302, a temperature detection element 306 is formed above the wiring 303 via an insulating film 304, and a recording element 309 is further formed above the temperature detection element 306 via an insulating film 307. The recording element 309 is formed in a Miranda shape in a plan view, and the temperature detection element 306 can be arranged in a rectangular shape below the recording element 309 so as to overlap with the recording element 309. The temperature detection element 306 is electrically connected to a corresponding portion of the wiring 303 via a conductive plug 305. The recording element 309 is electrically connected to another corresponding portion of the wiring 303 via a conductive plug 308. A protective film 310 and an anti-cavitation film 311 can be stacked in order to cover the entire structure. In the case of a Miranda shape, the recording elements 309 are arranged discretely, but are shown as a single unit in FIGS. 3(b) to 3(c) to make it easier to see the connection relationship.

[0034] The insulating film 302 and the like may be made of an insulating material such as silicon oxide. The wiring 303 may be made of a conductive material such as aluminum. The conductive plug 305 and the like may be made of a conductive material such as tungsten. The temperature detection element 306 may be made of a material having a relatively high electrical resistance such as titanium or titanium nitride. The recording element 309 may be made of a material having a relatively high electrical-thermal conversion efficiency such as tantalum silicon nitride. The protective film 310 may be made of an insulating material such as silicon nitride. The cavitation-resistant film 311 may be made of a material having a relatively high cavitation resistance such as tantalum.

[0035] A nozzle forming material 312 is disposed on the element substrate 5. Nozzles 313 are provided in the nozzle forming material 312 so as to correspond to the recording elements 309. The element substrate 5 and the nozzle forming material 312 may be collectively expressed as a nozzle substrate, a nozzle plate, or the like. The nozzle forming material 312 may be made of a material that can be molded relatively easily, such as a photosensitive resin.

[0036] In this way, the element substrate 5 has a multi-layer wiring structure in which the temperature detection element 306 is disposed in an intermediate layer between the layer of the wiring 303 and the layer of the recording elements 309. With this configuration, the temperature detection element 306 is provided for each of the multiple recording elements 309, making it possible to obtain temperature information corresponding to each individual recording element 309.

[0037] Although details will be described later, the state of ink ejected by driving the corresponding recording element 309 can be determined based on temperature information (detected temperature and its change state) obtained by the temperature detection element 306. This determination can be made by a temperature inspection unit, which is a logic circuit unit (not shown) provided on the element substrate 5. The determination result signal RSLT indicating the ink ejection state is a 1-bit signal in this example, which indicates "1" when ink is ejected appropriately (for ease of explanation, hereinafter referred to as "normal ejection") and indicates "0" when ink is not ejected appropriately (for ease of explanation, hereinafter referred to as "difficult to eject").

[0038] 4 shows an example of a system configuration for explaining a method for processing the temperature detection result by the temperature detection element 306. To detect the temperature of the recording element 309, in the print engine unit 417, the head I / F 427 includes a signal generation unit 7 and a determination result extraction unit 9. The signal generation unit 7 generates signals CLK, LT, BLE, DATA, HE, SDATA, Diref, and Ddth to be output to the element substrate 5.

[0039] The signal CLK is a clock signal for synchronously controlling the driving of each element in the element substrate 5. The signal LT is a latch signal for controlling the driving of the latch circuit in the element substrate 5. The signal BLE is a block enable signal for controlling the driving of the multiple recording elements 309 in the element substrate 5 in a time division manner. The signal DATA is a print data signal indicating whether or not to drive each recording element 309 in the element substrate 5. The signal HE is a heat enable signal for setting the driving time of each recording element 309 in the element substrate 5. The signal SDATA is a sensor selection signal for selecting a drive target from the multiple temperature detection elements 306 in the element substrate 5. The signal Diref is a constant current signal for controlling the driving of the constant current element in the element substrate 5. The signal Ddth is an ejection inspection threshold signal for inspecting the ink ejection state based on the driving of the recording elements 309 in the element substrate 5.

[0040] In the element substrate 5 driven based on the above-mentioned signal, a judgment result signal RSLT is generated based on temperature information obtained by the temperature detection element 306. The judgment result extraction unit 9 receives the signals LT, BLE, and SDATA from the signal generation unit 7, and also receives the judgment result signal RSLT from the element substrate 5.

[0041] Here, the sensor selection signal SDATA includes setting information such as information for setting the amount of current for the temperature detection element 306 selected as the driving target, and information on the output content of the determination result signal RSLT. For example, when a plurality of recording elements 309 are arranged to form two or more columns (e.g., five columns), the sensor selection signal SDATA includes column selection information for selecting a column and element selection information for selecting one of the elements in the column. Temperature information is detected by the temperature detection element 306 corresponding to a certain recording element 309 in the column selected by the sensor selection signal SDATA, and a 1-bit determination result signal RSLT is generated based on the temperature information and output from the element substrate 5.

[0042] The evaluation, judgment, or inspection of the ink ejection mode performed in this manner can be expressed as ejection evaluation, ejection judgment, or ejection inspection, respectively. The 1-bit judgment result signal RSLT is output to a predetermined number of rows of recording elements 309. For example, when a 1-bit judgment result signal RSLT is output to five rows of recording elements, a 2-bit judgment result signal RSLT is output when there are ten rows of recording elements. In this case, the 2-bit signal as the judgment result signal RSLT is output serially to the judgment result extraction unit 9.

[0043] The latch signal LT, block enable signal BLE, and sensor selection signal SDATA are fed back from the signal generation unit 7 to the judgment result extraction unit 9. The judgment result extraction unit 9 receives a judgment result signal RSLT based on temperature information detected by the temperature detection element 306 from the element substrate 5, and extracts the judgment result in each latch period in synchronization with the latch signal LT. If the judgment result is that ejection is difficult, the block enable signal BLE and sensor selection signal SDATA corresponding to the judgment result are stored in the RAM 421.

[0044] The print controller 419 refers to the block enable signal BLE and the sensor selection signal SDATA stored in the RAM 421 in this way, and based on them, erases the signal corresponding to the difficult-to-eject nozzle from the print data signal DATA of the corresponding block. In addition to erasing the signal, the print controller 419 adds a complementary signal to the print data signal DATA of the corresponding block, and outputs it to the signal generating unit 7. That is, the print controller 419 can identify the nozzle 313 in the print head 3 that is difficult to eject based on the determination result signal RSLT received from the element substrate 5, and corrects the print data signal DATA based on the identification result. This correction is performed so that the nozzle 313 that is difficult to eject is not driven and the nozzle 313 that is difficult to eject is complemented by another nozzle 313.

[0045] <Method of determining ink ejection state> FIG. 5 shows the detected temperature (referred to as sensor temperature T), which is the output waveform from the temperature detection element 306 when the recording element 309 is driven, and its time derivative (referred to as temperature change signal dT / dt). Here, the recording element 309 is driven by supplying a driving pulse 211 as a pulse-shaped driving signal. In the figure, the sensor temperature T is shown as a temperature (unit [°C]), but in reality it is detected by a potential difference (unit [V]) generated by supplying a constant current to the temperature detection element 306. In other words, the sensor temperature T is obtained by converting the detected potential difference. The temperature change signal dT / dt is shown as a time change (unit [mV / sec]) of the detected potential difference.

[0046] Waveform 201 shows the change in sensor temperature T in the case of normal ejection. In the process in which sensor temperature T rises and then falls based on the supply of heat enable signal HE, in the case of normal ejection, characteristic point 209 appears due to cooling caused by the tail of ink droplets ejected from nozzle 313 returning into nozzle 313. According to waveform 201, characteristic point 209 appears approximately 5.0 μsec after the supply of drive pulse 211, and after this characteristic point 209, sensor temperature T drops rapidly. On the other hand, in the case of difficulty in ejection, characteristic point 209 does not appear, but the waveform becomes like 202, and the drop in sensor temperature T is more gradual than in waveform 201 in the case of normal ejection.

[0047] In the temperature change signal dT / dt, a waveform 203 indicates the time differential of the waveform 201 in the case of normal ejection, and a waveform 204 indicates the time differential of the waveform 202 in the case of difficult ejection. Here, the waveform 203 (or 204) is output by passing the waveform 201 (or 202) through a filter circuit and an inverting amplifier, but may be obtained by equivalent arithmetic processing.

[0048] In the waveform 203, a peak 210 appears after the timing of the characteristic point 209 of the waveform 201. The waveform 203 is input to, for example, a comparator and compared with a discharge inspection threshold voltage TH that is set based on the discharge inspection threshold signal Ddth. As a result, in a section where the waveform 203 is equal to or higher than the discharge inspection threshold voltage TH (a section where dT / dt≧TH), a pulse 213 indicating normal discharge appears in the determination signal CMP. On the other hand, in the waveform 204, since the characteristic point 209 does not appear in the waveform 202, the peak becomes lower than the discharge inspection threshold voltage TH, and the pulse 213 does not appear in the determination signal CMP.

[0049] This determination signal CMP is output as the above-mentioned determination result signal RSLT, and in this manner, it becomes possible to evaluate the ink ejection state of the nozzles 313. The ejection inspection threshold voltage TH may be registered in advance in a non-volatile memory (not shown) in the print head 3.

[0050] <About time-division driving> In the recording device 1000, the recording speed can be increased by increasing the number of recording elements 309 included in the recording head 3. In such a recording head 3, if all of the multiple recording elements 309 are driven at once, potential fluctuations (noise) may occur due to the generation of a large current, so a method of driving the multiple recording elements 309 in sequence in blocks is typically used.

[0051] In this example, a method is adopted in which the multiple recording elements 309 are divided into two or more groups, and two or more recording elements 309 in each group are driven in sequence. The recording elements 309 that are driven approximately simultaneously between groups can be expressed as a block. For example, the number of groups is m (an integer of 2 or more), and the number of blocks is n (an integer of 2 or more). At this time, the recording elements 309 corresponding to the first blocks of the first to m-th groups are driven approximately simultaneously, and then the recording elements 309 corresponding to the second blocks of the first to m-th groups are driven approximately simultaneously. After that, the recording elements 309 corresponding to the third and subsequent blocks are driven in sequence in the same procedure, and then the n-th blocks of the first to m-th groups are driven, so that all of the multiple recording elements 309 are driven.

[0052] By repeating the above-mentioned series of driving operations while recording, the above-mentioned potential fluctuations that may have occurred during the operation are suppressed. Such a driving method is also called a time-division driving method, the above-mentioned groups are also called time-division groups, and the above-mentioned blocks are also called time-division blocks. The driving order of the blocks can be arbitrarily changed.

[0053] 6 shows an example of the configuration of the circuit section 60 capable of realizing the above-mentioned time-division driving, which is included in the element substrate 5. Here, the printhead 3 is equipped with 512 printing elements 309 (shown as Seg0 to Seg511 in the drawing), and the circuit section 60 is configured to be able to drive them in a time-division manner with 64 groups and 8 blocks.

[0054] For example, eight blocks (B#0, B#1, . . . B#7) in each group can be selectively driven by a three-bit block enable signal BLE. Here, an eight-bit signal developed by a decoder 324 is input to an AND circuit 323 of a corresponding block. A print data signal DATA is serially transferred to the element substrate 5 in synchronization with a clock signal CLK, input to a 64-bit shift register 321, and then latched by a latch circuit 322 based on a latch signal LT. The 64-bit signal latched by the latch circuit 322 is input to an AND circuit 323 of a corresponding group. In addition, a heat enable signal HE input via an inverter circuit 325 and a latch signal LT are input to each AND circuit 323. The output of the AND circuit 323 can control a switch element (not shown) for energizing the print element 309.

[0055] In this way, the block to be driven by the block enable signal BLE is driven for a period corresponding to the pulse width of the heat enable signal HE, for example, when the print data signal DATA is "1".

[0056] Generally, faster recording can be achieved by shortening the input period (latch period) of the latch signal; in other words, maximum speed recording is achieved by supplying the latch signal at the minimum input period (minimum latch period). The minimum latch period can be determined based on the time required for proper signal transfer in the circuit configuration according to this embodiment. In this embodiment, the transfer data is 480 bits and the transfer frequency is 160 MHz (6.25 μsec / bit), in which case the minimum latch period is 3.0 μsec.

[0057] FIG. 7 is a diagram for explaining the timing of input of the latch signal LT in this embodiment, with the horizontal axis representing the time axis.

[0058] The ▽ mark in the diagram indicates the timing of the input of the latch signal LT. With parameter K being an integer between 0 and 7, the signal blkK in the diagram corresponds to the block enable signal BLE in the period from the input of the latch signal LT to the input of the next latch signal LT for the corresponding block (B#K). In the above example (an example of 480-bit transfer data and a transfer frequency of 160 MHz), the period from one input timing to the next input timing is 3.0 μsec.

[0059] The ▼ marks in the figure indicate the timing of input of a column signal for synchronizing the driving of the print element array. The period from one input timing to the next input timing (column period) includes the period during which all of the signals blk0 to blk7 can be input, that is, the period during which each of the blocks can be driven, and the period can also be said to be determined by the column signal.

[0060] As shown in Fig. 7, the latch signal LT with an input period of 3.0 μsec is input eight times, so all blocks are selected and driven in 24.0 μsec. In the example of Fig. 7, the column period is set to 26.4 μsec, which further includes 2.4 μsec, which is 10%, in consideration of the error in the conveyance accuracy of the recording medium 2. In this embodiment, the conveyance speed of the recording medium 2 that realizes the maximum speed recording is set to 0.8 m / sec, the resolution at that time is set to 1200 dpi (distance between dots: 21.2 μm), and the conveyance accuracy of the recording medium 2 is calculated based on the deviation from this standard.

[0061] However, as described above, the characteristic point 209 appears approximately 5.0 μsec after the supply of the drive pulse 211 of the heat enable signal HE (see FIG. 5). Therefore, it can be said that it is difficult to execute the above-mentioned judgment of the ink ejection mode before the lapse of approximately 5.0 μsec when the characteristic point 209 may appear, depending on the latch signal LT with an input period of 3.0 μsec. On the other hand, if the latch period is extended, it is necessary to slow down the conveying speed. For example, if the latch period is set to 5.0 μsec, the conveying speed will be 0.48 m / sec, and the recording productivity (production efficiency of printed matter) may decrease by approximately 40%.

[0062] Therefore, as an example, when determining the ink ejection state, it is possible to make the supply state of the latch signal LT different from that in the case of normal printing. In this embodiment, the printing device 1000 includes, as operation modes, a printing mode in which printing is performed without performing ejection evaluation, and an evaluation mode in which printing for ejection evaluation is performed based on the printing, and the supply state of the latch signal LT can be switched depending on the operation mode.

[0063] -First Example 8 shows a flowchart showing the drive control of the recording apparatus 1000 according to the first embodiment. This flowchart is started based on an operational input from the user, and can be mainly performed by the controllers 401 and / or 419.

[0064] In step S801 (hereinafter simply referred to as "S801"; the same applies to other steps described below), a recording operation is started based on an operational input from the user.

[0065] In S802, the latch period is set to one for the print mode, the input period of the latch signal LT for the column period in this embodiment is set to 3.0 μsec, and the input quantity (supply quantity) is set to 8. The print operation in S801 can be performed by ejecting ink based on this setting.

[0066] In S803, it is determined whether or not the discharge evaluation has started. If the discharge evaluation has started, the process proceeds to S804, and if not, the process returns to S802.

[0067] In S804, the input period of the latch signal LT for the column period is set to 6.0 μsec, and the input quantity is set to 4. Fig. 9 is a diagram for explaining the input timing of the changed latch signal LT, similar to Fig. 7. According to the setting of S804, the latch signal LT with an input period of 6.0 μsec is input four times, so that in a certain column period, half of the blocks (B#0 to B#3 in this example) are selected and driven in 24.0 μsec. Then, in the next column period, the remaining blocks (B#4 to B#7 in this example) are selected and driven in 24.0 μsec. Then, because the latch period is 6.0 μsec, the characteristic point 209 appears about 5.0 μsec after the supply of the drive pulse 211 of the heat enable signal HE (see Fig. 5), and based on this, the discharge evaluation can be appropriately realized.

[0068] In S805, it is determined whether or not the discharge evaluation has been completed. If the discharge evaluation has been completed, the process proceeds to S806, and if not, the process returns to S804.

[0069] In S806, it is determined whether the recording operation is complete. If the recording operation is complete, this flowchart ends, and if not, the process returns to S802.

[0070] According to such drive control, in the recording mode, the recording is performed at high speed, and in the evaluation mode, the ejection evaluation is properly performed by supplying a latch signal LT with a longer input period than in the recording mode. In the evaluation mode, half of the blocks (B#0 to B#3 in this example) are driven in a certain column period, and the remaining blocks (B#4 to B#7 in this example) are driven in the next column period. Therefore, the resolution of the image formed by the recording for ejection evaluation during the evaluation mode is 600 dpi, but when returning to the recording mode, the resolution returns to 1200 dpi.

[0071] The operation of the evaluation mode may be started based on, for example, the elapsed time since the previous ejection evaluation, the accumulated time of the recording operation, etc. As described above, the recording medium 2 may be either a cut sheet or a rolled sheet. In the case of a cut sheet, the operation of the evaluation mode may be performed arbitrarily between recording on a certain sheet and recording on the next sheet in the recording mode, and the recording for ejection evaluation may be performed on an additional sheet or on the margin of the certain sheet or the next sheet. In the case of a rolled sheet, the operation of the evaluation mode may be performed arbitrarily between recording of a certain page and recording of the next page in the recording mode.

[0072] In summary, the recording device 1000 can switch between operation modes including a recording mode and an evaluation mode, and the supply mode of the latch signal LT can be changed depending on the operation mode. In this embodiment, in the recording mode, the latch signal LT with an input period of 3.0 μsec is input eight times for the column period, and in the evaluation mode, the latch signal LT with an input period of 6.0 μsec is input four times for the column period. According to such drive control, in the evaluation mode, the timing at which the characteristic points required for the discharge evaluation appear is guaranteed, so that appropriate discharge evaluation is realized, while in the recording mode, recording is appropriately performed at high speed and high resolution regardless of the timing of the characteristic points. In addition, during the evaluation mode, discharge evaluation is performed at the same conveying speed as in the recording mode without reducing the conveying speed of the recording medium 2, so that the productivity of recording is not reduced.

[0073] -Second Example In the above-described first embodiment, the input period and the input quantity of the latch signal LT are changed while the column period (26.4 μsec) is fixed. However, the column period may be changed. FIG. 10 is a diagram for explaining the timing of input of the latch signal LT after the change according to the second embodiment, similar to FIG. 9. This embodiment differs from the first embodiment in that in the evaluation mode, the column period is doubled (52.8 μsec), and the latch signal LT with an input period of 6.0 μsec is input eight times relative to the column period. Even with such drive control, it is possible to properly realize the ejection evaluation based on the characteristic point 209 that appears about 5.0 μsec after the supply of the drive pulse 211 of the heat enable signal HE (see FIG. 5). Therefore, even with this embodiment, high-speed printing is realized in the print mode, and ejection evaluation can be properly realized in the evaluation mode by supplying a latch signal LT with an input period longer than that of the print mode.

[0074] In addition, in light of the first and second embodiments, it is sufficient that the input period of the latch signal LT is long relative to the recording mode so that ejection evaluation can be properly performed in the evaluation mode. Since the reduction in resolution during the evaluation mode does not substantially affect the printing productivity itself, it can be said that the number of inputs of the latch signal LT in a column period (one period) is not an issue.

[0075] -Third Example The recording device 1000 may include two or more recording modes with different recording speeds, for example, a high-speed recording mode and a low-speed recording mode. For example, the high-speed recording mode may be used when recording productivity is prioritized and a large amount of printed matter, such as office documents, needs to be prepared in a short time (first recording mode). On the other hand, the low-speed recording mode may be used when image quality is prioritized and time is required for ink fixation, such as by drying processing (second recording mode, which may also be expressed as high-quality mode).

[0076] In such a case, the manner in which the latch signal LT is supplied may differ between when the high-speed recording mode is switched to the evaluation mode and when the low-speed recording mode is switched to the evaluation mode.

[0077] In the following example, in the high-speed recording mode, when the recording medium 2 is transported at a speed of 0.8 m / sec, the input period of the latch signal LT for a column period (26.4 μsec) is set to 3.0 μsec and the input quantity is set to 8. In the low-speed recording mode, when the recording medium 2 is transported at a speed of 0.3 m / sec, the input period of the latch signal LT for the same column period is set to 8.0 μsec and the input quantity is set to 8.

[0078] Fig. 11 shows a flowchart showing the drive control of the recording apparatus 1000 according to the third embodiment, similar to Fig. 8. This flowchart differs from the flowchart of the first embodiment in that S1101 is added between S801 and S802, and S802 to S806 are performed if the determination is Yes at S1101, and S1102 to S1106 are performed if the determination is No at S1101.

[0079] In S1101, it is determined whether or not the mode is the high-speed recording mode. If the mode is the high-speed recording mode, the process proceeds to S802, and if not (if the mode is the low-speed recording mode), the process proceeds to S1102.

[0080] In S1102, the latch period is set to one for the print mode, the input period of the latch signal LT for the column period in this embodiment is set to 8.0 μsec, and the input quantity is set to 8. The print operation in S801 can be performed by ejecting ink based on this setting.

[0081] In S1103, it is determined whether or not the discharge evaluation has started. If the discharge evaluation has started, the process proceeds to S1104, and if not, the process returns to S1102.

[0082] In S1104, the input period of the latch signal LT relative to the column period is set to 8.0 μsec, and the input quantity is set to 8. According to the setting in S1104, the latch period is 8.0 μsec, so that ejection evaluation can be appropriately realized based on the feature point 209 that appears approximately 5.0 μsec after the supply of the drive pulse 211 of the heat enable signal HE (see FIG. 5). In this example, since the same conditions as in S1102 are set again, this step may be omitted (the setting of the latch signal LT does not need to be changed).

[0083] In S1105, it is determined whether or not the discharge evaluation has been completed. If the discharge evaluation has been completed, the process proceeds to S1106, and if not, the process returns to S1104.

[0084] In S1106, it is determined whether the recording operation is complete, and if the recording operation is complete, this flowchart ends, and if not, the process returns to S1102.

[0085] To summarize, in this embodiment, the input period of the latch signal LT in the low-speed recording mode is 8.0 μsec. As described above, the characteristic point 209 appears approximately 5.0 μsec after the supply of the drive pulse 211 of the heat enable signal HE (see FIG. 5). Therefore, according to the latch signal LT with an input period of 8.0 μsec, it is possible to appropriately determine the ink ejection mode described above approximately 5.0 μsec after the characteristic point 209 appears. Therefore, in the evaluation mode, it is sufficient that the latch signal LT is supplied in the same manner as in the low-speed recording mode, and there is no need to change the supply mode of the latch signal LT in the low-speed recording mode (S1104 can be omitted). On the other hand, in the high-speed recording mode, the same drive control as in the first embodiment described above is performed.

[0086] In this embodiment, two types of recording modes, a high-speed recording mode and a low-speed recording mode, are exemplified, but the number of recording modes may be three or more. In addition, the input period and the input quantity of the latch signal LT in those modes may be different from the parameters exemplified above. In such a case, it is sufficient to make changes within the scope of the embodiment, for example, S1104 is not omitted, and suitable parameters are set for the input period and the input quantity of the latch signal LT so that the discharge evaluation is appropriately realized.

[0087] According to the above embodiment, in the evaluation mode, the timing at which the characteristic points necessary for the discharge evaluation appear is guaranteed, while in the recording mode, recording is performed regardless of the timing of the characteristic points, and discharge evaluation is performed without lowering the conveying speed of the recording medium 2 during the evaluation mode. This makes it possible to improve the productivity of recording and the quality of recording. Note that each control signal capable of realizing such drive control can be generated by the signal generating unit 7, but may also be generated by the controllers 401 and / or 419, or may be generated by the element substrate 5.

[0088] <Program> The present invention may be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in a computer of the system or device read and execute the program. For example, the present invention may be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0089] <Other> In the above description, the recording device 1000 using the inkjet recording method is taken as an example, but the recording method is not limited to the above. The recording device 1000 may be a single-function printer having only a recording function, or a multifunction printer having multiple functions such as a recording function, a FAX function, and a scanner function. It may also be a manufacturing device for manufacturing color filters, electronic devices, optical devices, microstructures, etc. using a predetermined recording method.

[0090] In addition, the term "recording" in this specification should be interpreted broadly. Therefore, the form of "recording" does not matter whether the object formed on the recording medium is significant information such as characters or figures, and also does not matter whether it is visible to humans or not.

[0091] In addition, the term "recording medium" should be interpreted broadly, just like the above-mentioned "recording." Therefore, the concept of a "recording medium" includes not only commonly used paper, but also any material capable of receiving ink, such as cloth, plastic film, metal plate, glass, ceramics, resin, wood, leather, etc.

[0092] Furthermore, "ink" should be interpreted broadly, just like the above-mentioned "recording". Therefore, the concept of "ink" includes not only liquid that is applied onto a recording medium to form an image, design, pattern, etc., but also accompanying liquid that can be used for processing the recording medium, processing the ink (for example, solidifying or insolubilizing the coloring material in the ink applied to the recording medium), etc. From this perspective, the recording head may be expressed as a liquid ejection head, etc., and the recording device may be expressed as a liquid ejection device, etc.

[0093] In addition, in the embodiments, each element is named based on its main function, but the functions described in the embodiments may be sub-functions and are not strictly limited to those expressions. Furthermore, those expressions can be replaced with similar expressions. In the same spirit, the expression "unit" can be replaced with "tool," "component," "member," "structure," "assembly," etc. Alternatively, those expressions may be omitted or added.

[0094] In addition, two or more elements exemplified as selectable in the embodiments are not strictly limited to the examples, and may be arbitrarily combined, for example, each of the two or more exemplified elements may be additionally or alternatively selected. As an example, when two elements A and B can be arbitrarily combined, it may be expressed as "A and / or B" or "at least one of A and B" to indicate that it is either A only, B only, or both A and B.

[0095] <Summary of the embodiment> Some features exemplified in the embodiments are summarized as follows: [1] A recording device having a plurality of nozzles for performing recording by ejecting ink, a plurality of heating elements arranged corresponding to the plurality of nozzles, each of which heats ink to cause the ink to be ejected from a corresponding nozzle; A plurality of temperature detection elements provided corresponding to the plurality of heating elements; an inspection means for inspecting the state of ink ejection from the nozzles based on signals from the plurality of temperature detection elements; and a signal generating means for generating a signal for driving the plurality of heating elements, a recording mode in which recording is performed by the plurality of heating elements without performing an inspection by the inspection means, and an inspection mode in which inspection is performed by the inspection means based on the recording performed by the plurality of heating elements, The signal generating means periodically generates a column signal that defines a period during which each of the heating elements can be driven, and periodically generates a latch signal for driving a target of the heating elements among the heating elements for a column period that is one period of the column signal, and sets a period for generating the latch signal longer in the inspection mode than in the recording mode. A recording device comprising: [2] In the inspection mode, the signal generating means generates latch signals such that, after a certain latch signal is supplied, the next latch signal is supplied at least after a timing at which a characteristic point corresponding to a peak in a waveform of a time derivative of the signal waveform obtained from the temperature detection element appears. The recording device according to [1], [3] When a time from when the certain latch signal is supplied to when the characteristic point appears is a first time, The signal generating means generates a latch signal in a cycle that is shorter than the first time in the recording mode. The recording device according to [2], [4] The column period in the recording mode and the column period in the inspection mode are equal to each other. The recording device according to any one of [1] to [3], [5] In the inspection mode, the signal generating means generates a smaller number of latch signals per column period than in the recording mode. The recording device according to [4], [6] The recording medium is further provided with a conveying means for conveying the recording medium, The conveying speed of the recording medium by the conveying means is equal in the recording mode and the inspection mode. The recording device according to [5], [7] The column period in the inspection mode is longer than the column period in the recording mode. The recording device according to any one of [1] to [3], [8] The number of latch signals generated by the signal generating means for each column period is equal in the recording mode and the inspection mode. The recording device according to [7], [9] The recording medium is further provided with a conveying means for conveying the recording medium, The conveying speed of the recording medium by the conveying means is equal in the recording mode and the inspection mode. The recording device according to [8],

[10] the recording mode is a first recording mode, the first recording mode being one of a plurality of recording modes; the plurality of recording modes include a second recording mode in which a period of the latch signal generated by the signal generating means with respect to a column period is equal to or greater than a reference period; a column period in the first recording mode and a column period in the inspection mode are equal to each other and are larger than a column period in the second recording mode; When the operation mode is changed from the second recording mode to the inspection mode, the signal generating means does not change the period of the latch signal generated with respect to the column period. The recording device according to any one of [1] to [6],

[11] the plurality of recording elements are divided into two or more groups, and driven by a time division driving method in which two or more recording elements in each group are driven in sequence as a block; The signal generating means generates a column signal so as to define a period during which each of all the blocks can be driven. The recording device according to any one of [1] to

[10] ,

[12] A program for causing a computer to function as each element of the recording device according to any one of [1] to

[11] . The program may be stored in a computer-readable storage medium so as to be executable by one or more processor circuits with a memory.

[0096] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0097] 1000: printing apparatus, 3: print head, 306: temperature detection element, 309: printing element, 313: nozzle, 401: main controller, 419: print controller, 7: signal generation unit, 9: judgment result extraction unit.

Claims

1. A recording device having a plurality of nozzles for performing recording by ejecting ink, a plurality of heating elements arranged corresponding to the plurality of nozzles, each of which heats ink to cause the ink to be ejected from a corresponding nozzle; A plurality of temperature detection elements provided corresponding to the plurality of heating elements; an inspection means for inspecting the state of ink ejection from the nozzles based on signals from the plurality of temperature detection elements; and a signal generating means for generating a signal for driving the plurality of heating elements, a recording mode in which recording is performed by the plurality of heating elements without performing an inspection by the inspection means, and an inspection mode in which inspection is performed by the inspection means based on the recording performed by the plurality of heating elements, The signal generating means periodically generates a column signal that defines a period during which each of the plurality of heating elements can be driven, and periodically generates a latch signal for driving a target of the heating elements among the plurality of heating elements for a column period that is one period of the column signal, and sets a period for generating the latch signal longer in the inspection mode than in the recording mode. A recording apparatus comprising:

2. In the inspection mode, the signal generating means generates latch signals such that, after a certain latch signal is supplied, the next latch signal is supplied at least after a timing at which a characteristic point corresponding to a peak in a waveform of a time derivative of the signal waveform obtained from the temperature detection element appears.

2. The recording apparatus according to claim 1.

3. When a time from when the certain latch signal is supplied to when the characteristic point appears is a first time, In the recording mode, the signal generating means generates a latch signal at a period shorter than the first time.

3. The recording apparatus according to claim 2.

4. The column period in the recording mode and the column period in the inspection mode are equal to each other.

2. The recording apparatus according to claim 1.

5. In the inspection mode, the signal generating means generates a smaller number of latch signals per column period than in the recording mode.

5. The recording apparatus according to claim 4.

6. The recording medium is further provided with a conveying means for conveying the recording medium, The conveying speed of the recording medium by the conveying means is equal in the recording mode and the inspection mode.

6. The recording apparatus according to claim 5.

7. The column period in the inspection mode is longer than the column period in the recording mode.

2. The recording apparatus according to claim 1.

8. The number of latch signals generated by the signal generating means for each column period is equal in the recording mode and the inspection mode.

8. The recording apparatus according to claim 7.

9. The recording medium is further provided with a conveying means for conveying the recording medium, The conveying speed of the recording medium by the conveying means is equal in the recording mode and the inspection mode.

9. The recording apparatus according to claim 8.

10. the recording mode is a first recording mode, the first recording mode being one of a plurality of recording modes; the plurality of recording modes include a second recording mode in which a period of the latch signal generated by the signal generating means with respect to a column period is equal to or greater than a reference period; a column period in the first recording mode and a column period in the inspection mode are equal to each other and are larger than a column period in the second recording mode; When the operation mode is changed from the second recording mode to the inspection mode, the signal generating means does not change the period of the latch signal generated with respect to the column period.

2. The recording apparatus according to claim 1.

11. the plurality of heating elements are divided into two or more groups, and driven by a time division driving method in which two or more heating elements in each group are driven in sequence as a block; The signal generating means generates a column signal so as to define a period during which each of all the blocks can be driven.

2. The recording apparatus according to claim 1.

12. A program for causing a computer to function as each element of the recording device according to any one of claims 1 to 11.

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