JP6685657B2 - Inkjet recording apparatus, temperature control method and program - Google Patents

Description

  The present invention relates to an inkjet recording apparatus and a recording head temperature control method.

  As one example of the inkjet system, there is a system in which the ink is ejected by utilizing the phenomenon that bubbles are generated in the ink by heating the ink by the ejection heater in the recording head. In particular, when such an ejection heater is used, the temperature of the ink in the recording head may rise as the ejection characteristics of the ink change, and therefore it is necessary to control the temperature to an appropriate temperature by temperature management.

  However, in order to measure the temperature with the recording head, a means for mounting an expensive thermistor with high measurement accuracy on the recording head, or a storage unit for performing correction instead of using an inexpensive diode sensor with many measurement errors It is necessary to take measures to mount the recording head on the recording head. There was a cost issue. On the other hand, in the technique disclosed in Patent Document 1, a plurality of types of temperature sensors having different measurement accuracy are provided in the recording head. Specifically, a small number of expensive temperature sensors with high measurement accuracy are provided as compared with inexpensive temperature sensors with relatively low measurement accuracy, and the former corrects the measured value of the latter. As a result, it is possible to improve the accuracy of temperature measurement in the recording head, and it is possible to realize appropriate temperature control of the recording head at a relatively low cost. On the other hand, in such a technique, in addition to the temperature measurement during the recording operation, the temperature measurement for periodically obtaining the calibration value is also performed, so that the number of times the temperature sensor is switched increases.

  Further, in recent years, the print head has been becoming longer and finer for the purpose of improving the print speed and the image quality, and there has never been a conventional operation in which ink is intensively ejected only at a specific portion of the print head. Realization of the method is required. Therefore, a long and fine recording head is equipped with multiple temperature sensors, these temperature sensors are finely controlled, and the temperature information on the recording head is widely acquired within a limited period of time. There is a technology to grasp the discharge status in detail. FIG. 1 is a diagram showing an example of a lengthened recording head. When recording with the recording head shown in FIG. 1, temperature measurement is performed by switching between the temperature sensor 1002 and the temperature sensor 1013. By controlling each part of the recording head to an appropriate temperature based on the acquired temperature information, optimum recording can be realized in the elongated recording head. On the other hand, when such an elongated recording head is adopted, the number of times the temperature sensor is switched increases and the set period increases.

JP-A-2000-334958

  However, in the related arts such as Japanese Patent Application Laid-Open No. 2004-163242, much attention has been paid to the improvement of the measurement accuracy of each element at the time of measuring the temperature of the recording head, but the optimum control of the timing of performing the temperature acquisition processing is not considered. In particular, timing control when temperature acquisition is performed while switching a plurality of temperature sensors is not considered. In addition, it is general to provide a recording pause period after the setting is changed and before the temperature is measured. Therefore, when the temperature sensor on the recording head is finely switched, the number of times of setting switching increases and the recording suspension period increases, which causes a problem of deterioration of recording performance.

The inkjet recording apparatus of the present invention includes a recording head including an ink ejection port, an energy generating element that generates energy used to eject the ink, and a plurality of temperature sensors for measuring temperature. Of the plurality of temperature sensors, a temperature sensor to be used for measuring the temperature of the recording head, a temperature measurement setting unit that performs setting for connecting the AD converter, and a temperature sensor connected by the setting are used. A temperature measurement control unit that measures the temperature of the recording head, the temperature measurement control unit performs the temperature measurement while the recording head is not performing the recording operation, and the temperature measurement setting unit parts are have row the setting during a period for the period and the next temperature measurement of the temperature measurement previously performed, the setting by the temperature measuring setting unit, performed the last time Characterized in that it is performed in parallel with other measures not temperature measurement period between periods for recording the period of temperature measurement.

  According to the present invention, the temperature information acquisition period can be shortened.

It is a figure which shows the example of the recording head lengthened. 1 is a perspective view showing a schematic configuration of an inkjet recording apparatus according to a first embodiment. FIG. 3 is a block diagram showing a control configuration of the inkjet recording apparatus in FIG. 2. 6 is a block diagram showing a configuration for performing a process related to temperature measurement of the recording head in the first embodiment. FIG. 6 is a flowchart showing a relationship between a process relating to printhead temperature measurement and an operation sequence of a print process in the first embodiment. 6 is a flowchart showing details of processing related to temperature measurement in the first embodiment. 6 is a timing chart illustrating an arbitration method of an AD converter use request according to the first embodiment. 6 is a timing chart illustrating a temperature information acquisition operation of the recording head in the first embodiment. FIG. 3 is a diagram showing an example of a recording head according to the first embodiment.

  Embodiments for carrying out the present invention will be described below with reference to the drawings.

[Embodiment 1]
FIG. 2 is a perspective view showing a schematic configuration of an inkjet recording apparatus suitable for applying this embodiment. This ink jet recording apparatus creates recording information and form information supplied from an external information source such as a host computer externally connected by a network or a direct interface, and a corresponding character pattern or form pattern according to a macro command or the like. Then, an image is formed on a recording sheet, which is a storage medium.

  The image processing unit 2001 has functions such as decoding processing and binarization processing of the input compressed data. Further, the image processing unit 2001 has a CPU inside for various kinds of processing, and also has a role of controlling the entire recording apparatus.

  The recording head 2002 is connected to an ink tank that contains a plurality of color inks such as black, cyan, magenta, and yellow. The recording head is arranged so that nozzles for each ink color are arranged in a line such as black, cyan, magenta, and yellow along the scanning direction of arrow X1.

  FIG. 9 is a diagram showing an example of the recording head in this embodiment. FIG. 9 shows a recording head composed of one chip, but a recording head composed of a plurality of chips may be adopted in this embodiment. The chip C1 is provided with four nozzle rows, and each nozzle row may correspond to the same ink color or different ink colors. Although not shown in FIG. 9, an ejection heater that generates thermal energy used for ejecting ink is provided at a position corresponding to each nozzle. Further, sub-heaters H1 and H2 used for temperature control of the chip are provided at the left and right ends of the chip C1. Further, temperature sensors S1 to S9 are provided on the left and right of each nozzle row and on the upper and lower ends of the chip C1. These temperature sensors are composed of semiconductors, and can measure the temperature of the chip according to their positions. Based on the measurement results of the temperature sensors S1 to S9, the recording control unit 2003 optimally controls the sub heaters H1 and H2 and the ejection heater during the recording operation, which enables stable ink ejection and high quality. Record can be realized.

  The recording control unit 2003 monitors the recording command signal transmitted from the image processing unit 2001 via the flexible cable, determines whether the recording command signal is invalid, and determines whether or not electricity is applied to the heating element. It has a function to instruct.

  The carriage 2004 is equipped with a recording head 2002 and a recording controller 2003, and can move in the reciprocating main scanning directions X1 and X2. The carriage 2004 is at the home position shown by P in FIG. 2 during standby such as a state where no recording operation is performed. While being guided by the guide rod G, the carriage 2004 is moved in the main scanning directions X1 and X2 by a moving mechanism (not shown).

  Further, the paper feed roller 2005, together with the auxiliary roller 2006, holds the recording paper 2008 as a recording medium and intermittently conveys it in the sub-scanning direction of the arrow Y. The paper feed roller 2007 feeds the recording paper 2008 and holds the recording paper 2008 like the paper feed roller 2005 and the auxiliary roller 2006.

  Next, a basic reciprocal recording operation with the above configuration will be described. The carriage 2004 at the home position P during standby moves in the forward scan direction X1 in response to a recording start command. Along with this, the recording head 2002 ejects ink from each of the plurality of ink ejection ports according to the image data, and performs recording such as recording on the recording paper 2008 with the ink. When the recording of one line of image data up to the edge of the recording paper 2008 is completed, the paper feed roller 2005 rotates in the arrow direction to feed the recording paper 2008 in the Y direction by a predetermined width. Subsequently, while the carriage 2004 is moving in the backward scan direction X2, ink is ejected from a plurality of nozzles of the recording head 2002 according to the image data, and recording such as recording is performed on the recording paper 2008. Then, it returns to the original home position P. After that, the paper feed roller 2005 again feeds the recording paper 2008 in the Y direction by a predetermined width. By repeating the head scanning operation and the paper feeding operation as described above, images are sequentially recorded on the recording paper 2008.

  In the main body (not shown) of the inkjet recording apparatus of this example, a motor driver for driving a carriage motor for driving a carriage, a paper feeding motor for driving a paper feeding roller, a paper transportation motor for paper transportation driving, and the like is provided. Have. In addition, it has a driver for driving the print head for driving the print head.

  FIG. 3 is a block diagram showing a control configuration of the recording apparatus in FIG. As shown in FIG. 3, the image processing unit 2001 includes a CPU 3001, a data decoding unit 3002, a binarization processing unit 3003, an SRAM 3004, an encoder 3005, a recording command unit 3006, an AD measuring unit 3007, a DRAM 3008, a ROM 3009, and a LAN control unit 3010. including.

  The CPU 3001 is the CPU of the image processing unit 2001. The CPU 3001 is composed of, for example, a high-speed RISC CPU, and comprehensively controls access to various devices connected to the system bus. The ROM 3009 stores a control program for the CPU 3001 and data necessary for controlling the inkjet recording apparatus. The CPU 3001 performs control based on a control program stored in the ROM 3009, a control program stored in the SRAM 3004 or the DRAM 3008, and the like.

  Further, the CPU 3001 is configured to be able to communicate with an external device such as a host computer connected to the external network 3011 via the LAN control unit 3010. The external network 3011 receives the compressed image data input from the host computer. Control between blocks in the image processing unit 2001 and communication of image data are performed via a data bus. In FIG. 3, the image processing unit 2001 communicates with the host computer via an external network, but it is also possible to connect to the host computer via an interface such as a USB (not shown) to perform communication. .

  The data decoding unit 3002 performs a decoding process on image data in a compressed state.

  The image processing unit 3003 performs conversion into binary data or the like based on the decoded image data.

  The encoder 3005 detects the position information of the carriage 2004.

  The print command unit 3006 generates print data to be supplied to the print head based on the binary data converted by the image processing unit 3003. The print command unit 3006 also generates a print command signal and a heating timing signal in the form of an electrical signal based on the position information of the carriage 2004 detected by the encoder 3005, and the print control unit 2003 mounted on the carriage 2004. Output to.

  The AD measurement unit 3007 is responsible for processing regarding the temperature measurement of the recording head 2002. The print head temperature information acquired by the AD measurement unit 3007 is transmitted to the print control unit 2003. According to this temperature information, the recording control unit 2003 executes optimum control during the recording operation.

  In the present embodiment, the process relating to the temperature measurement of the print head, which is executed by the AD measurement unit 3007, is a setting process necessary for temperature measurement (hereinafter, temperature measurement setting) process and an AD converter is used to acquire a measurement value. It is divided into processing (hereinafter referred to as AD measurement). Hereinafter, the AD measurement for obtaining the temperature measurement value will be referred to as a temperature measurement AD measurement or a temperature measurement. In the present embodiment, the temperature measurement setting is performed before the temperature measurement command signal is issued to reduce the time required to measure the temperature of the recording head. The temperature of the recording head is measured immediately in response to the temperature measurement command signal issued based on the operating position of the recording head or the timer setting that is grasped by the detection value of the encoder 3005. The temperature measurement setting is performed in parallel with other measurement operations such as recording density detection, and it is not necessary to provide a recording pause period for temperature measurement setting. As a result, it is possible to shorten the recording head temperature acquisition period at the time of recording and improve the recording performance.

  FIG. 4 is a block diagram showing a configuration for performing processing relating to temperature measurement of the print head in this embodiment.

  The encoder 3005 is used to detect the position information of the carriage 2004 on which the recording head 2002 is mounted.

  The print command unit 3006 generates a heating timing signal in the print head based on the position information of the carriage 2004 detected by the encoder 3005.

  The recording control unit 2003 issues a heating command for ink to the recording unit 4012 by using the heating timing signal input from the recording command unit 3006 as a trigger.

  The AD measurement unit 3007 performs AD conversion control for various sensors, including the temperature measurement of the recording head. The AD measurement unit 3007 includes an AD converter 4007 and an arbitration circuit 4006 that arbitrates access to the AD converter. In addition, it further has a temperature measurement part selection unit 4003, a temperature measurement number instruction unit 4004, a temperature measurement order instruction unit 4005, a temperature measurement setting unit 4009, a temperature measurement control unit 4002, and a temperature measurement instruction unit 4008.

  The temperature measurement site selection unit 4003 holds temperature measurement site information, the temperature measurement number command unit 4004 holds the temperature measurement number, and the temperature measurement order command unit 4005 holds the temperature measurement order. Further, the AD measuring unit 3007 has a continuous mode. This continuous mode is a mode in which the temperature measurement operation is repeated unless the recording process is completed or a stop command is explicitly issued. In the continuous mode, execution / non-execution of the operation can be set, and the set value is held in the temperature measurement number instruction unit 4004 together with the temperature measurement number. These can be set by the CPU 3001.

  The temperature measurement setting unit 4009 includes the temperature measurement including the connection information of the selector 4010 on the recording head side based on the information such as the temperature measurement site, the number of times of temperature measurement, and the temperature measurement order, which are necessary to measure the temperature of the recording head. Generate a device switching command. Hereinafter, the temperature measurement device switching command is also referred to as a temperature measurement setting command (setting command).

  The selector 4010 is connected to a plurality of temperature sensors 4011 (temperature sensors S1 to S9 in FIG. 9) mounted in the recording head, and selects from a plurality of temperature sensors according to the selector connection information transmitted from the temperature measurement setting unit 4009. Select one. By the selector 4010, the temperature measurement in the present embodiment is switched between the temperature sensor S1 to the temperature sensor S9. In this embodiment, the completion of the switching setting of the selector 4010 is the completion of the temperature measurement setting.

  The temperature measurement control unit 4002 controls the temperature measurement of the recording head. Further, the temperature measurement control unit 4002 performs transfer setting and sequence control of switching setting performed from the temperature measurement setting unit 4009 to the selector 4010 mounted on the recording head 2002 via the recording command unit 3006.

  The temperature measurement command unit 4008 generates the temperature measurement timing of the print head based on the position information of the print head detected by the encoder 3005 and issues a temperature measurement command signal (measurement command).

  The details of this embodiment will be described below with reference to the flowcharts of FIGS. 5 and 6. Specifically, the steps from the step of receiving image data to the step of printing by the printing apparatus will be described in order.

  FIG. 5 is a flowchart showing the relationship between the process relating to the printhead temperature measurement and the operation sequence of the print process in this embodiment.

  In step S5001, when a recording request is issued from the host computer, the image processing unit 2001 prepares for recording such as image processing.

  After that, in step S5002, processing related to temperature measurement, that is, temperature measurement setting and temperature measurement of the recording head are performed. Details of this step will be described later with reference to FIG.

  Then, in step S5003, the print data generated in step S5001 is transferred to the head, and the print processing is performed based on the temperature information of the print head acquired in step S5002.

  In step S5004, the recording command unit 3006 determines whether all the scheduled recording processes have been completed. If not completed, in order to continue the recording process, the flow proceeds to step S5002, and the temperature measurement setting and temperature measurement of the recording head are performed again. On the other hand, if all the scheduled recording processes have been completed, the process of this flow ends.

  FIG. 6 is a flowchart showing the details of the process relating to temperature measurement performed in step S5002 of FIG. The temperature measurement process of the recording head is started at the timing when the recording process is not performed.

  First, in step S6001, the temperature measurement site selection unit 4003 selects a temperature measurement site based on the set value that is previously set in the register of the temperature measurement control unit 4002 from the CPU 3001.

  Subsequently, in step S6002, the temperature measurement number instruction unit 4004 selects the temperature measurement order based on the set value set in the register of the temperature measurement control unit 4002.

  In step S6003, the temperature measurement order command unit 4005 selects the number of times of temperature measurement based on the set value set in the register of the temperature measurement control unit 4002. The processing from step S6001 to step S6003 is positioned as an initial setting.

  Then, in step S6004, temperature measurement setting is performed based on the various information selected in the above processing. Specifically, the temperature measurement setting unit 4009 generates a temperature measurement device switching command based on the above various information. The generated temperature measurement device switching command includes connection information of the selector 4010 on the recording head side, and can be transmitted to the selector 4010 via the recording command unit 3006. The selector 4010 performs switching setting based on the received connection information.

  Next, in step S6005, the encoder 3005 detects the position information of the recording head. In the ink jet recording apparatus of the present embodiment, the recording start timing and the timing for measuring the temperature of the recording head are determined based on the position information of the recording head at the time of recording and the timer setting at the time of recording stop.

  In step S6006, the temperature measurement instruction unit 4008 determines whether or not it is the timing of recording, using the position information of the recording head detected by the encoder 3005 and the count value of the timer. At the timing of recording, noise is included in the measurement result, so the temperature of the recording head is not measured, and the flow advances to step S6005. Also, since the temperature measurement setting command issuance timing is also controlled by the print head position information and the timer count value, the timing at which the print head setting is switched according to the temperature measurement setting command and the temperature measurement timing are exclusive. Controlled. On the other hand, if it is the timing at which recording is not performed, the flow advances to step S6007.

  In step S6007, the temperature measurement command unit 4008 issues a temperature measurement command signal as an internal signal.

  In step S6008, the temperature measurement control unit 4002 issues an AD converter use request to the arbitration circuit 4006 according to the temperature measurement command signal. The arbitration circuit 4006 arbitrates the AD converter use request issued from each master circuit, and issues the use right to one specific place.

  In step S6009, the temperature measurement control unit 4002 continues to wait until it acquires the right to use the AD converter. If the AD converter use right is acquired, the flow proceeds to step S6010.

  Then, in step S6010, the temperature measurement control unit 4002 measures the temperature of the recording head using the AD converter.

  After measuring the temperature, in step S6011, the temperature measurement control unit 4002 determines whether the operation mode is the continuous mode. The continuous mode refers to a mode in which the temperature measurement operation is repeated unless the recording process ends or a stop command is explicitly issued. If it is determined that the mode is not the continuous mode, the flow proceeds to step S6013. If it is determined that the mode is the continuous mode, the flow proceeds to step S6012.

  In step S6012, the recording command unit 3006 determines whether recording has been completed. If the recording process has not been completed, the flow advances to step S6004 to perform temperature measurement setting and subsequent processes again.

  On the other hand, if it is determined in step S6011 that the mode is not the continuous mode, or if it is determined in step S6012 that the recording process has been completed, it is determined in step S6013 that temperature measurement is complete, and the process of this flow ends.

  FIG. 7 is a timing chart for explaining the arbitration method for the AD converter use request according to this embodiment. Hereinafter, the arbitration method of the AD converter use request implemented in the arbitration circuit 4006 will be described with reference to the timing chart of FIG. 7.

  The AD converter according to the present embodiment handles not only the temperature information of the recording head but also data of various sensors such as detection of the edge of the recording paper and detection of the recording density. Therefore, in addition to the measurement request issued from the temperature measurement control unit 4002 to the AD converter 4007, AD measurement requests are issued from a plurality of masters not shown in FIG. It is necessary to perform arbitration processing. The arbitration process is based on the round-robin method, but the request regarding the measurement of the printhead temperature needs to be promptly responded. Therefore, the arbitration process is performed with a high priority. This is because it is necessary to prevent the noise from being mixed in the temperature measurement value by controlling the heat pulse generation timing associated with the recording process and the head temperature information measurement timing to be exclusive.

  In the case of FIG. 7, each master issues an AD measurement request to the arbitration circuit 4006 in the order of application A, application B, application C, and temperature measurement application D. Here, the use A, the use B, and the use C are uses other than the temperature measurement use, and may be, for example, detection of recording density or detection of the edge of recording paper. As a result of the arbitration processing, AD measurement is performed in the order of application A, application B, temperature measurement application D, and application C.

  The arbitration processing in the arbitration circuit 4006 prioritizes the temperature measurement request D, and determines the order of use of the AD converters for other requests by the round robin method. The round robin method is an algorithm that gives resource usage rights to all masters that can issue requests in order and evenly. The present embodiment is premised on that the usage A, the usage B, and the usage C operate in round robin, and the resource usage right is such as usage A, usage B, usage C, usage A, usage B, usage C. Assigned in order. If the master issues a resource use request at the timing when this resource use right is assigned, the corresponding master can use the resource. For example, when the usage right of the resource is assigned to the usage A, if the usage A that is the master issues the resource usage request, the resource can be used in the usage A. On the other hand, when the usage right of the resource is assigned to the usage B, the usage A cannot use the resource even if the usage A as the master issues the resource usage request. You need to wait until the resource usage rights are assigned.

  Next, the arbitration operation in this embodiment will be specifically described. First, since only the measurement request for the use A is issued, the AD measurement regarding the use A is immediately started. After that, since the measurement requests for the use B and the use C are issued, the AD measurement for the use B is performed after the measurement of the use A is completed. As for the use C, the processing operation of the use A and the use B, which previously issued the measurement request, is waited until the processing operation of the use A and the use B is completed. Then, the AD measurement of the temperature measurement application D is performed, and then the AD measurement of the application C is performed. By performing such arbitration processing, the generation timing of the heat pulse for heating the ink and the temperature information measurement timing of the head are controlled to be exclusive to prevent noise from being mixed into the temperature measurement value. In addition, the AD measurement for other uses is surely performed, and the responsiveness is realized with respect to the requirement regarding the printhead temperature measurement.

  FIG. 8 is a timing chart for explaining the temperature information acquisition operation of the print head in this embodiment. Operations such as the first temperature measurement, the second temperature measurement setting, the second temperature measurement, and the third temperature measurement setting will be described in order. At the start of the timing chart, the first temperature measurement setting necessary for the first temperature measurement has already been made, and the selector 4010 in the recording head 2002 is selected to be connected to the first temperature sensor 4011 (temperature sensor S1). It is assumed that That is, it is assumed that step S6004 has already been performed for the first temperature measurement at the start point of the timing chart.

  First, the first temperature measurement period will be described. The temperature measurement command signal is issued based on the recording head position information detected by the encoder. It is necessary to measure the temperature of the recording head during the issuance period of the temperature measurement command signal, which is the timing when the recording operation is not performed. When it is determined that the recording operation is not performed by the processing of steps S6005 and S6006, the temperature measurement command signal is issued in step S6007. The temperature measurement command signal issuance period is a temperature measurement dedicated period, which is from timing T1 to timing T2 as shown in FIG. Hereinafter, the processing performed in the processing flow of FIG. 6 at each timing will be referred to in parentheses.

  At the timing T1, the temperature measurement command signal is issued (step S6007), and the temperature measurement AD measurement Req (request) is issued to the arbitration circuit 4006 according to the temperature measurement signal (step S6008). Here, the AD measurement request is an AD converter use request. In the arbitration circuit 4006, the right to use the AD converter is given to the temperature measurement master (step S6009), and the AD measurement which is the first temperature measurement is executed (step S6010).

  At the timing T3, since the measurement of the printhead temperature information is completed, the AD converter side returns the temperature measurement AD measurement Ack (reply) to the AD measurement unit 3007 which is the temperature measurement master together with the temperature measurement value. The AD measurement unit 3007 holds the returned temperature measurement value in a register included in the temperature measurement control unit 4002 so that it can be read from the CPU at any timing.

  The issuance period of the temperature measurement command signal from timing T1 to timing T2 is kept sufficiently longer than the period of use of the AD converter from timing T1 to timing T3. As a result, even if a delay occurs in switching the AD converter, no problem occurs in the temperature measurement process.

  Subsequently, the second temperature measurement setting period will be described. If the first temperature measurement is performed and the temperature measurement value can be read from the CPU (after the temperature measurement performed last time), various settings are changed to perform the second temperature measurement (second temperature measurement). Measurement setting) will be carried out. The settings necessary for performing temperature measurement are the temperature measurement site, the number of times of temperature measurement, and the temperature measurement order. Of these, the temperature measurement part is held in the temperature measurement part selection part 4003, the temperature measurement number is held in the temperature measurement number command part 4004, and the temperature measurement order is held in the temperature measurement order command part 4005. It is possible to set the default. The temperature measurement control unit 4002 performs switching setting to the selector 4010 mounted on the recording head 2002 based on the set values of the temperature measurement site, the number of times of temperature measurement, and the temperature measurement order (step S6004).

  The selector 4010 has a function of connecting the temperature sensor 4011 and the AD converter 4007, and can be appropriately changed according to the setting content. When changing the setting of the selector, the temperature measurement setting unit 4009 issues a selector switching Req to the recording command unit 3006. The issuance timing of the selector switching Req can be the timing at which the measurement setting unit 4009 obtains information that the temperature measurement value can be read from the CPU. In FIG. 8, the selector switching Req for the second temperature measurement is issued at the timing T3, but may be the end timing (timing T2) of the AD measurement dedicated period for the first temperature measurement. Upon receiving this selector switching Req, the recording command unit 3006 issues a temperature measurement device switching command to the selector 4010 via the recording control unit 2003. At timing T4, since the setting change is completed by the selector 4010, a selector switching Ack is transmitted from the recording command unit 3006 to the temperature measurement setting unit 4009, and the second temperature measurement setting is completed.

  Although not limited to this, in this embodiment, the temperature measurement device switching command is transferred to the print head side through the same path as the print data. By converting the control into a command along the same path as the recording data, it is possible to reduce the number of signal lines in the contact portion of the recording head and to increase the efficiency of control of the recording head. Further, it can be transmitted at a timing earlier than the transmission of recording data.

  Next, the second temperature measurement will be described. The second temperature measurement is performed after the second temperature measurement setting and is performed based on the second temperature measurement setting. As an example, the selector 4010 in the recording head 2002 is connected to the second temperature sensor 4011 (temperature sensor S2). The recording command signal and the temperature measurement command signal are issued based on the position information of the recording head measured by the encoder 3005.

  It is necessary to measure the temperature of the recording head during a period during which a temperature measurement command signal is issued (a period dedicated to AD measurement for temperature measurement), which is a timing when the recording operation is not performed. While the print data is being transferred to the print head, the temperature of the print head is not measured and the process waits. The recording head heating signal (heat pulse) is issued only at the timing of performing the recording process, and does not overlap with the issuance timing (temperature measurement timing) of the temperature measurement command signal. This makes it possible to prevent noise from entering the temperature information (decrease in accuracy). By exclusively controlling the recording period and the temperature measurement timing in this way, the accuracy of the temperature data is improved.

  Further, the issuance timing of the temperature measurement setting command does not overlap with the issuance timing (temperature measurement timing) of the temperature measurement instruction signal. This is because the timing is controlled so that the temperature measurement setting command is issued immediately before the recording data is sent. As a result, it is possible to acquire the measurement data under the condition set by the correct command without fail.

  An AD measurement Req (request) for temperature measurement is issued to the arbitration circuit 4006 at the timing when the temperature measurement instruction signal is issued. In the arbitration circuit 4006, the AD converter usage right is given to the temperature measurement master, and the temperature measurement is executed. Then, when the measurement of the printhead temperature information is completed, the AD converter side sends back the temperature measurement AD measurement Ack (reply) to the AD measurement unit 3007 which is the temperature measurement master together with the temperature measurement value. The AD measurement unit 3007 holds the returned temperature measurement value in a register included in the temperature measurement control unit 4002 so that it can be read from the CPU at any timing. Here, the second temperature measurement is completed.

  Finally, the third temperature measurement setting will be described. When the second temperature measurement is performed and the temperature measurement value can be read from the CPU, various settings are changed (third temperature measurement setting) to perform the third temperature measurement. . The operation content here is the same as the second temperature measurement setting.

  In this way, the temperature measurement operation of the recording head is realized by repeatedly performing the temperature measurement setting and the temperature measurement as described above. The temperature measurement setting is executed before the temperature measurement process and during the transfer of the recording data, thereby enabling quick response when the temperature measurement command signal is input. In the temperature measuring process, the temperature acquisition timing of the print head and the print data transfer timing are exclusively executed to improve the accuracy of the temperature data. This temperature acquisition timing may be determined based on the operating state of the recording head, or may be determined based on a timer.

  As described above, the present embodiment has the recording head having the selector that switches the connection between the AD converter and the temperature sensor in order to perform the temperature measurement process using the AD converter. Further, it further has a temperature measurement setting unit that executes a setting command issuing process required for measuring the temperature of the printhead prior to the temperature measurement instruction. As a result, the temperature acquisition period at the time of recording can be shortened, and the temperature can be reliably acquired in a short time while avoiding the heating period of the recording head associated with the recording process. Further, in addition to the above, by providing a temperature measurement control unit that performs temperature information acquisition with high priority, it is possible to reduce costs by reducing the number of AD converters for measurement. This is a technique that leads to an improvement in recording performance. The recording head temperature measuring means described in the present invention can be realized as an electric circuit by one ASIC.

(Other embodiments)
The above-described embodiment relates to a mode in which the ink is heated by using the discharge heater to perform the discharge, but the application of the present invention is not limited to this mode. For example, even in the method of ejecting ink using a piezo element, the present invention can be similarly applied to the mode in which the temperature of the recording head (ink) is measured.

  Further, the present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or an apparatus via a network or a storage medium, and one or more processors in a computer of the system or the apparatus execute the program. It can also be realized by a process of reading and executing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

1001 ink ejection ports 1002 to 1013 temperature sensor 3001 CPU
3002 data decoding unit 3003 binarization processing unit 3004 SRAM
3005 encoder 3006 recording command section 3007 AD measuring section 3008 DRAM
3009 ROM
3010 LAN control unit 3011 LAN
2001 Image Processing Unit 2002 Recording Head 2003 Recording Control Unit 2004 Carriage 2007 Paper Feed Roller 2006 Auxiliary Roller 2005 Paper Feed Roller 2008 Recording Paper (Recording Medium)
4002 temperature measurement control unit 4003 temperature measurement site selection unit 4004 temperature measurement number command unit 4005 temperature measurement order command unit 4006 arbitration circuit 4007 AD converter 4008 temperature measurement command unit 4009 temperature measurement setting unit 4010 selector 4011 temperature sensor

Claims (9)

A recording head including an ink ejection port, an energy generating element that generates energy used for ejecting ink, and a plurality of temperature sensors for temperature measurement,
Of the plurality of temperature sensors, a temperature sensor that should be used to measure the temperature of the recording head, and a temperature measurement setting unit that performs settings for connecting an AD converter,
A temperature measurement controller that measures the temperature of the recording head by using the temperature sensor connected by the setting,
The temperature measurement control unit performs the temperature measurement while the recording operation is not performed by the recording head,
It said temperature measuring setting section have rows the set between the time for the period and the next temperature measurement of the temperature measurement performed last,
The inkjet recording apparatus , wherein the setting by the temperature measurement setting unit is performed in parallel with other measurement that is not temperature measurement during a period between a temperature measurement period performed last time and a recording period . The temperature measurement control unit performs the temperature measurement according to a measurement command,
The temperature measurement setting unit performs the setting according to a setting command,
The inkjet recording apparatus according to claim 1, wherein the setting command is issued prior to the measurement command.   The inkjet recording apparatus according to claim 1, wherein a recording operation is performed between the setting and the temperature measurement. The usage right of the AD converter is issued to only one of the temperature measurement and the other measurement, and the temperature measurement or the other measurement for which the usage right is not issued is used by the AD converter. The inkjet recording apparatus according to claim 1 , further comprising an arbitration unit that waits until the right is acquired. The inkjet recording apparatus according to claim 4 , wherein the arbitration unit issues a right to use the AD converter with high priority to the temperature measurement. It said temperature measurement control unit, an ink jet recording apparatus according to any one of claims 1 to 5, characterized in that it comprises a selector for switching the connection between said AD converter and said plurality of temperature sensors. Said temperature measurement control unit, an ink jet recording apparatus according to any one of claims 1 to 6, characterized in that to determine the period for the temperature measurement on the basis of the position information or the timer setting of the recording head . A recording process in which the temperature is measured by a plurality of temperature sensors and ink is ejected from the ejection port of the recording head by using the energy generated by the energy generating element,
A temperature measurement setting step of performing setting for connecting a temperature sensor to be used for measuring the temperature of the recording head among the plurality of temperature sensors, and an AD converter;
Using a temperature sensor connected by the setting, a temperature measurement control step of measuring the temperature of the recording head,
In the temperature measurement control step, the temperature measurement is performed during a period when the recording operation is not performed by the recording head,
The temperature measuring setting step, have row the setting during a period for the duration of the temperature measurement previously performed the next temperature measurement,
The temperature control method , wherein the setting in the temperature measurement setting step is performed in parallel with other measurement that is not temperature measurement during a period between a temperature measurement period performed last time and a recording period . Program for functioning as an ink jet recording apparatus according to any one of the computer of claims 1 to 7.