JP2007015254A - Recorder and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of detecting a residual amount of ink by preventing erroneous detection of the residual amount of ink, and an inkjet recorder using the method. <P>SOLUTION: This recorder has both of residual amount detection functions respectively using an optical detection method and a dot-counting method. In order to solve the problem that optical detection is missed by an external cause, when an accumulated value of a consumption amount of ink measured by counting of dots is less than a prescribed threshold, an optical judgment result of the absence of the residual ink in a first space is ignored only at the first time. In the case where the absence of ink is judged by the optical detection the number of times not less than a prescribed value, the optical detection judgment result is prioritized even when the accumulated value of the consumption amount of ink by the counting of dots is less than the threshold, thereby eliminating the mismatching in the detection of the residual amount of ink. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink remaining amount detecting method and a recording apparatus, and more particularly to an ink remaining amount detecting method for an ink tank that supplies ink to a recording head that performs recording in accordance with an ink jet method, and a recording apparatus using the method.

  In an ink jet recording apparatus that records an image by ejecting ink from a recording head, if the ink runs out during the recording operation, the output image may be faded, so that the ink is filled It is necessary to perform the recording operation again. For this reason, the recording throughput is reduced and the recording medium is wasted. Further, if a recording operation (recording head drive) is performed in a state where there is no ink in the recording head, there is a possibility that an abnormality such as an ejection failure may occur in the recording head.

  In order to reduce these problems, the ink jet recording apparatus has a function of detecting the remaining amount of ink in an ink tank that stores ink for supplying ink to the recording head. According to this ink remaining amount detection function, the remaining amount of ink in the ink tank is detected and the remaining amount is displayed, or a warning is given to the user of the apparatus when the remaining amount is low. The recording operation can be stopped. Specifically, there are various methods for detecting the remaining amount of ink in the ink tank.

  As one of the methods, there is a method in which some kind of sensor is provided in the ink tank and the remaining amount of ink is directly measured. As this sensor, one using an electrode or an optical sensor can be considered. The method of using electrodes for the sensor is to estimate the remaining amount of ink by providing two electrodes in contact with the ink inside the ink tank and measuring the resistance value between the electrodes that changes according to the remaining amount of ink. is there. Also, the method using an optical sensor is provided with an optical sensor including a light source and a light receiving unit in the vicinity of the ink tank, makes light incident on the ink in the ink tank, and changes depending on the remaining amount of ink and the presence or absence of ink. Reflected light or transmitted light is detected to detect the remaining amount of ink and the presence or absence of ink. Such an ink remaining amount detection method is called a “sensor method”.

  As another method different from the sensor method described above, the ink consumption is indirectly estimated by counting the number of ink droplet ejections and multiplying the estimated ink amount per ejection by the number of ejections. There is something to do. This method is called a “dot count method”.

  Since each method has advantages and disadvantages, a plurality of remaining amount detection methods may be used in combination to complement each other. Such a remaining amount detection method is disclosed, for example, in Patent Document 1 below.

In order to improve user convenience, it has also been devised to provide a memory function to the ink tank. By writing the ink information and the remaining amount of ink in a memory such as an EEPROM provided in the ink tank, it is possible to prevent the ink tank from being erroneously installed, or to manage the remaining amount even if the same ink tank is used in multiple inkjet recording devices. It can be carried out. By combining with conventional remaining amount detection, more accurate remaining amount detection is possible. Such an ink tank is disclosed in Patent Documents 2 and 3 below, for example.
JP 2002-127454 A JP 09-314861 A Japanese Patent Application Laid-Open No. 07-309018

  In the case of an ink remaining amount detection method using both a sensor method using an optical sensor and a dot count method, the presence / absence of ink (or ink remaining amount) in the first space of the ink tank divided into two spaces is determined optically. Detection is performed using a sensor, and ink remaining amount determination in the second space is detected using a dot count method. However, the optical sensor that determines the presence or absence of ink in the first space can detect the remaining amount accurately due to external factors such as electrical noise interfering with the sensor output value or the light receiving unit receiving disturbance light. May not be possible. That is, it may be determined that there is no ink even though there is ink in the ink tank. For this reason, even when the presence or absence of ink in the first space is determined, the ink remaining amount is detected by dot count, and if the ink usage integrated value by dot count is less than or equal to a threshold value, detection detection using an optical sensor is performed. The method of ignoring the result is used to achieve consistency of the remaining amount of ink.

  However, when the ink remaining amount in the first space is obtained as an integrated value of ink usage based on dot count, the amount per discharge depends on the variation in the ejection amount of each printing device and the usage environment (environment temperature and humidity) of the printing device. Since the ink amount is different or does not correspond to a change in the ink amount due to ink evaporation, the remaining amount may not be detected accurately even in the dot count method. That is, there is a case where ink is used up in the first space even though the ink consumption by the dot count method is less than the predetermined threshold value. In addition, in the method of managing the remaining amount of ink by providing a memory in the ink tank, if the ink tank is used in a model that does not support reading and writing of the memory, the ink consumption measured by the dot count is written. Therefore, there is a risk that a difference may occur between the remaining amount of ink written in the memory and the actual ink amount. Similarly, even if the ink tank is not provided with a memory and the dot count integrated value is stored in the memory in the printing apparatus, there is a concern that the same phenomenon may occur if the memory use format differs for each printing apparatus. The Therefore, when determining the presence or absence of ink in the first space, the method of ignoring the detection result of the presence or absence of ink using the optical sensor until the ink usage integrated value by the dot count method reaches a predetermined value is detected by the optical sensor. In this case, it is determined that there is no ink in the first space, but since the integrated value of ink consumption by the dot count is less than the threshold value, the determination result is ignored. As a result, although it is actually ink LOW (a state where the remaining amount of ink is low), the user cannot be notified of this and printing is continued, and a recording operation is performed without ink. There was a fear. There is a concern that the recording head may be damaged by performing the recording operation without ink, which may reduce the convenience for the user.

  In order to solve the above problem, the ink remaining amount detection method of the present invention has the following configuration.

  Ink remaining amount in an ink tank having a first space for storing ink and a second space for storing an ink absorber that has absorbed the ink to supply to a recording head that performs recording in accordance with an inkjet method In the remaining ink amount detection method for detecting ink, there are at least two types of detection methods, and priority is given to the result of the first detection method up to a certain ink usage threshold, but the specified number of times when the ink usage is less than the threshold As described above, there is provided an ink remaining amount detection method characterized in that priority is given to the result of the second detection method when it is detected that there is no ink in the second detection method.

  Furthermore, the threshold value of the ink usage amount is the same or different depending on the type of ink.

  Furthermore, the specified number of times is two or more.

  Further, the first detection method is a dot count method, and the second detection method is an optical detection method.

  Further, the optical detection method makes light incident on the first space, detects reflected light or transmitted light of the light, and based on the detected light, the remaining in the first space. It has the discrimination | determination process which discriminate | determines the presence or absence of quantity ink.

  Further, the dot counting method includes a counting step for counting the number of ink ejections from the recording head, and the ink counted in the counting step until it is determined in the determination step that there is no remaining ink in the first space. An integration step of integrating the number of ejections, a determination step of comparing the integrated value with the threshold value and determining that there is no remaining ink in the first space if the integrated value is equal to or greater than the threshold value; After determining that there is no amount of ink, the integration step of integrating the number of ink ejections in the second space and the remaining number of ink tanks by comparing the number of ink ejections in the second space with a specified threshold value And a determination step of determining the presence or absence of ink.

  Furthermore, the prescribed threshold value for the number of ejections in the second space is the same or different depending on the type of ink.

  Further, the determination step result and the determination step result are recorded in a memory attached to the ink tank or in a main body memory.

  Further, in the determination step, the number of times of optical detection determination is one and the ink usage integrated value by the dot count is less than the threshold value, or the remaining amount of ink in the first space recorded in the memory associated with the ink tank or the main body memory If the determination result of the determination step is that no ink is present when the ink is not zero, the optical detection determination result indicating no ink is rejected.

  Furthermore, the ink use amount integrated value by the dot count when the determination result by the predetermined number of executions of the determination step is no ink is less than the threshold value, or the first recorded in the memory or main body memory associated with the ink tank When the ink remaining amount in the space is not zero, the optical detection determination result without ink is given priority.

  Furthermore, it is preferable that a recording control unit is provided for controlling the recording operation by the recording head to stop when the determination unit determines that there is no remaining ink in the ink tank.

  The recording head preferably includes an electrothermal transducer for generating thermal energy applied to the ink in order to eject the ink using thermal energy.

  According to the present invention, when the remaining amount of ink in the ink tank is detected using a plurality of types of detection methods, the remaining amount of ink can be detected more accurately.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  First, the configuration of the ink jet recording apparatus will be described. FIG. 6 is a perspective view showing a schematic configuration of a recording apparatus including a recording head that performs recording in accordance with an ink jet method according to a typical embodiment of the present invention. In this embodiment, as shown in FIG. 6, the recording head 1 is connected together with an ink tank 7 for supplying ink to the recording head 1 to constitute an ink cartridge 20. A non-volatile memory (for example, EEPROM) for writing individual ink information is attached to the ink cartridge. An electrode is provided at a contact point with the carriage 2, and writing and reading are performed from there. In this embodiment, the ink cartridge 20 is configured such that the recording head 1 and the ink tank 7 can be separated as will be described later. However, an ink cartridge in which the recording head and the ink tank are integrated may be used. .

  Further, a light reflecting surface for detecting the remaining amount of ink is provided on the bottom surface of the ink tank 7, and the internal structure of the ink tank 7 has a structure as shown in FIG. Therefore, hereinafter, when referring to the internal structure of the ink tank 7, the reference numbers used in FIG. 1 or FIG. 2 will be used.

  Furthermore, this recording head is provided with means (for example, an electrothermal converter, a laser beam, etc.) for generating thermal energy as energy used for performing ink ejection, particularly in the ink jet recording system, and the thermal energy. As a result, the recording density is increased and the resolution is increased by using a system that causes a change in the state of ink.

  In FIG. 6, a recording head 1 is mounted on a carriage 2 in a posture to eject ink downward in the figure, and ink droplets are ejected while moving the carriage 2 along a guide shaft 3 like a recording sheet. An image is formed on a recording medium (not shown). The carriage 2 is moved left and right (reciprocating) through the timing belt 5 by the rotation of the carriage motor 4. An engagement claw 6 is provided on the carriage 2, and the ink tank 7 is fixed to the carriage 2 by engaging with an engagement hole 7 a of the ink tank. When the recording for one scanning of the recording head is completed, the recording operation is interrupted, the recording medium located on the platen 8 is conveyed by a predetermined amount by driving the feed motor 9, and then the carriage 2 is again moved along the guide shaft 3. Then, image formation for the next one scan is performed.

  On the right side of the apparatus main body, a recovery device 10 that performs a recovery operation for keeping the ink discharge state of the recording head 1 in a good state is disposed. The device 10 includes a cap 11 that caps the recording head 1, and the recording head 1. A wiper 12 for wiping the ink discharge surface, and a suction pump (not shown) for sucking ink from the ink discharge nozzles of the recording head 1 are provided.

  Further, the driving force of the feed motor 9 for conveying the recording medium is transmitted to the automatic paper feeder (ASF) 13 in addition to being transmitted to the original recording medium conveying mechanism.

  Further, on the side of the recovery device 10, an optical unit 14 that constitutes a reflective sensor for detecting the remaining amount of ink, which includes an infrared LED (light emitting element) 15 and a phototransistor (light receiving element) 16 is provided. . The light emitting element 15 and the light receiving element 16 are attached so as to be aligned along the recording sheet conveyance direction (direction of arrow F). The optical unit 14 is attached to a chassis 17 of the apparatus main body. When the ink cartridge 20 is mounted on the carriage 2 and moved to the right from the position shown in FIG. 4, the ink cartridge 20 is positioned on the optical unit 14. The ink state can be detected by the optical unit 14 from the bottom surface of the ink tank 7.

  Next, a control configuration for executing the recording control of the above-described apparatus will be described.

  FIG. 7 is a block diagram showing the configuration of the control circuit of the recording apparatus. In FIG. 7 showing the control circuit, 1700 is an interface for inputting a recording signal, 1701 is an MPU, 1702 is a ROM for storing a control program executed by the MPU 1701, and 1703 is various data (supplied to the recording signal and the recording head 1). This is a DRAM for storing recording data and the like. Reference numeral 1704 denotes a gate array (GA) that controls supply of print data to the printhead 1 and also performs data transfer control among the interface 1700, MPU 1701, and RAM 1703. Reference numeral 1705 denotes a head driver for driving the recording head 1, and reference numerals 1706 and 1707 denote motor drivers for driving the feed motor 9 and the carriage motor 4, respectively.

  The operation of the control configuration will be described. When a recording signal enters the interface 1700, the recording signal is converted into recording data for printing between the gate array 1704 and the MPU 1701. The motor drivers 1706 and 1707 are driven, and the recording head 1 is driven according to the recording data sent to the head driver 1705 to perform recording.

  Reference numeral 1710 denotes a display unit including an LCD 1711 for displaying various messages related to the recording operation and the wiping state of the recording apparatus, and LED lamps 1712 of various colors for notifying the state of the recording operation and the recording apparatus.

  The gate array 1704 is provided with a so-called dot counter (not shown), which is a droplet discharge number detecting means for counting the number of ink droplets discharged from the recording head. In this dot counter, it is possible to count both ink droplets ejected to form an image and ink droplets ejected during preliminary ejection performed as part of the recovery process. .

  Further, in the recording apparatus of the present embodiment, the ink consumption in each ink tank in various suction recovery processes is experimentally obtained in advance, and the consumption weight when the suction recovery process is executed can be managed for each ink tank. it can. That is, the amount of ink consumed in the recording apparatus of the present embodiment is the sum of the number of dots counted by the dot counter described above multiplied by the discharged droplet weight and the consumed weight of the suction recovery process described above. It is possible to calculate by

  The calculated ink consumption is written into the memory of the ink tank 7 at a predetermined timing. In this recording apparatus, similar information can be written and backed up in a nonvolatile memory (EEPROM: not shown) provided in the recording apparatus.

  The operation of the ink remaining amount detection unit 25 that detects the presence or absence of ink in the ink tank 7 integrated with the recording head 1 is controlled by the MPU 1701.

  Next, the principle of ink remaining amount detection will be described. In this case, the principle of detecting the remaining amount of ink in the ink tank using a sensor, in particular, an optical sensor will be described. Actually, the ink jet recording apparatus is provided with a basic configuration for detecting the remaining amount of ink as shown in FIG.

  First, in FIG. 1, 101 is an ink tank made of a light transmissive material such as transparent plastic for containing ink to be supplied to the recording head, and 102 is a supply for supplying ink from the ink tank 1 to the recording head. Mouth, 103 is an air communication port for performing gas-liquid exchange accompanying ink consumption, 104 is ink of colors such as black, cyan, magenta, and yellow, which are normally used in color printers, and 105 is a recording head for recording. In order to stably supply ink, an ink absorber such as polyurethane having an appropriate capillary force so as to generate an appropriate negative pressure in the ink tank, 106 is positioned at an appropriate position in the ink tank. (A left half space in FIG. 1) a partition plate 107 for holding the ink, which is not absorbed by the ink absorber 105 (hereinafter referred to as “raw ink”) It is called).

  The lower part of the partition plate 106 communicates with the right half space and the left half space of the ink tank 101. By gradually supplying the raw ink 107 to the ink absorber 105 in this way, the negative pressure is kept constant while the raw ink 107 remains.

  Reference numeral 108 denotes an LED serving as a light source for detecting the presence or absence of the raw ink 7. As this LED, an LED that emits light having a wavelength of 555 nm that hardly passes through any of the four colors of black, cyan, magenta, and yellow, for example, HBG5066X manufactured by Stanley Electric Co., Ltd. can be used. Further, reference numeral 109 denotes a photodetector such as a silicon photodetector which has sufficient sensitivity to the wavelength of light from the LED 108. As shown in FIG. 1, the photodetector 109 converts the light emitted from the LED 108 into an ink tank. 101 and the raw ink 107 are arranged so as to receive light.

  Note that light emission control of the LED 108 and processing based on light detected by the light detector 109 are performed by a CPU or the like provided in the ink jet recording apparatus.

  Reference numeral 110 denotes a memory which is provided with electrodes on the recording head or carriage side to which the ink tank is attached, and writes ink information.

  In the example shown in FIG. 1, the light path from the LED 108 to the light detector 109 is a straight line, and a transmission type sensor in which light that has passed through the ink in the ink tank is detected by the light detector 109 is used. According to the principle of detecting the remaining amount of ink, it is sufficient that there is a sufficient difference in the light amount level detected by the photodetector 109 when there is no ink in the ink tank. Is provided on the same side of the ink tank, irradiates light to the bottom surface of the ink tank made of a light-transmitting material, receives the light reflected on the bottom surface and returning to the photodetector 109 again, and the remaining amount of ink A reflection type sensor configured to perform detection may be used.

  Next, FIG. 2 shows an example using a reflective sensor. A description of portions common to FIG. 1 is omitted. FIG. 2A shows a state with raw ink, and FIG. 2B shows a state without raw ink. In the state with raw ink, when the remaining amount of ink in the ink tank is sufficient, the inner surface of the ink tank is filled with ink 107 as shown in FIG. 2A, and the illumination light emitted from the light source 111 is emitted. Most of 114 passes through the prism 115 and passes into the ink 107, and the illumination light 114 for detecting the remaining amount of ink passes through the interface between the ink 107 and the prism 115 without being reflected. Therefore, the reflected light from the prism 115 cannot be obtained, and the sensor 112 can inspect that the remaining amount of ink is sufficient because there is no reflected light. On the other hand, as shown in FIG. 2B, when the ink amount is empty or small, the illumination light 114 from the light source 111 is reflected in the prism 115, and the illumination light 114 is totally reflected at the interface between the prism 115 and air. Therefore, the reflected light 116 enters the sensor 112. Thereby, it can be detected that the remaining amount of ink is empty or low. In the embodiment, a reflection type is used.

  Next, a detailed configuration of the ink remaining amount detection unit 25 will be described with reference to FIG.

  In the configuration shown in FIG. 8A, based on the control signal from the MPU 1701, the controller 32 outputs a pulse signal having a predetermined duty (DUTY) ratio (%) to the LED drive circuit 30, and the duty The light emitting element 15 constituting the optical unit 14 is driven according to the ratio to irradiate the bottom of the ink tank 7 with infrared light.

  The infrared light is reflected by the reflecting surface at the bottom of the ink tank 7 and returns to the light receiving element 16 constituting the optical unit 14. The light receiving element 16, which is a phototransistor, converts the received infrared light into an electrical signal and outputs the electrical signal to a low-pass filter (LPF) 31. The low pass filter (LPF) 31 cuts high frequency noise from the electric signal input from the light receiving element 16 and sends only a low frequency signal to the controller 32. The controller 32 performs A / D conversion on the signal from the low-pass filter (LPF) 31 to convert it into a digital signal. Then, the converted value is transferred to the MPU 1701.

  As shown in FIG. 8B, the light-emitting element 15 is an infrared LED that emits infrared light 28, and the light-receiving element 16 receives infrared light 29 according to the intensity of the received light. It is a phototransistor that outputs an electrical signal. As shown in FIG. 4, these infrared LEDs and phototransistors are arranged so as to be aligned along the recording sheet conveyance direction.

  Basically, when the ink jet recording apparatus has the above-described configuration, the ink remaining amount detection in the ink tank is executed according to a sequence as shown in the flowchart of FIG.

  The MPU 1701 starts counting the number of ink discharges immediately after the ink tank is newly installed in the recording apparatus. In step S1, the count value is set to 0 and initialized.

  When the recording head to which ink is supplied from the ink tank 101 in step S2 ejects ink, in the next step S3, the number of ink ejections is counted, and the counted number is added to the count value. Further, the count number is recorded in the memory 110 of the ink tank.

  In the next step S4, light is emitted from the light source 111 and the light is received by the photodetector 112. Further, in step S5, it is checked whether or not the amount of received light is zero.

  Here, since the ink tank 101 is filled with the raw ink 107 in the first stage, the light from the light source 111 passes through the prism 115 and is absorbed by the ink, and the output of the photodetector 112 is offset and Excluding the noise background, the value becomes “zero”, and the process returns to step S2. On the other hand, as the recording operation proceeds, the ink is consumed and the raw ink 107 gradually decreases. When the raw ink 107 is eventually exhausted, the irradiation light 114 from the light source 111 reflects the prism 115 and the reflected light 116 is detected by light. A non-zero output is obtained at the detector 112 and at the photodetector 112. As described above, when the output change of the photodetector 112 is received, the CPU determines that the raw ink 107 has run out, and the process proceeds to step S6.

  In step S6, if the integrated value of ink consumption based on dot count is equal to or greater than the threshold value, the process proceeds to step S9. As a threshold value at this time, a value corresponding to 60% of the raw ink amount is defined. However, the threshold value is not particularly limited and is not limited to this. Regarding the cause of being less than the threshold value, 1: the ink remarkably evaporated, and the initial ink amount when the ink tank was mounted decreased. 2: When using an ink tank with a model that does not support the memory function, the ink consumption measured by the dot count is not written to the ink tank memory, so the ink amount written in the memory and the actual ink A difference occurred in the amount, and the ink in the first space was exhausted when the ink consumption by the dot count was less than the threshold value. 3: The optical sensor was erroneously detected due to the influence of electrical noise or the like. The following three points are considered. Here, if the integrated value of the ink consumption by the dot count is less than the threshold value and the process proceeds to step S7, if it is the first time (N = 1), the optical sensor is erroneously detected, and the result of determining no ink is ignored. Return to. If N> 1, the process proceeds to step S8 to check whether there is an erroneous detection. If it is determined that the light quantity is zero or more (N = 4) four times or more, the reason of 1 or 2 is suspected and it is determined that there is no ink, and step S9 Proceed to If the number of times of determination is the second time and the third time, steps S4 to S8 are repeated until the determination is made four times. However, although the number of times of discrimination is four or more here, this is not limited as long as it is a plurality of times.

  In step S9, a display (ink LOW) notifying that the raw ink is exhausted and the ink is low is displayed on the monitor, and the fact that the raw ink is exhausted is written in the memory 110 of the ink tank.

  After the ink LOW is displayed in step S9, the process proceeds to step S10 where dot counting is independently performed in the absorber. Each time ink discharge occurs in step S11 due to the recording operation, the number of discharges is added in step S12, and the integrated value of the ink consumption based on the dot count of the absorber is compared with a prescribed threshold value in step S13. If it exceeds the threshold value, the process proceeds to step S14, and if it is less than the threshold value, the process returns to step S11. The threshold value at this time is 80 to 90% of the ink amount held in the absorber. This threshold differs depending on the type of ink, and is a value that takes error into consideration. The threshold is not limited to this.

  In step S14, an indication that the user has run out of ink (ink end) is displayed, and the fact that the ink has ended is recorded in the memory 110 of the ink tank. This makes it possible to always notify the user that the ink is being used even if the same tank is used in another machine that can read the ink tank memory, so the head is damaged by ejecting an empty ink tank. Can be prevented.

  Although the above description has been given of the case where an ink tank with a memory is used, the same applies to the case where an ink tank without a memory is used. In this case, the dot count integrated value and the remaining amount determination result may be recorded in the main body memory, not in the memory associated with the ink tank.

  Alternatively, the integrated value and the determination result may be recorded in the memory in the main body at the same time as the ink tank memory.

  Although the above description did not explain the processing after the ink tank replacement, the processing after replacement with a new ink tank is performed in the processing shown in FIG. 3, and the processing in steps S15 and S16 as shown in the flowchart of FIG. Add it. S15 reads the memory of the installed tank and extracts the ink remaining amount information. If it is not the ink end, it is considered that the tank has been replaced, and the dot count value written in the memory of the replaced tank through step S17 is set as the dot count value. Reset as the initial count value (initial value is zero for a new tank), and return to step S2.

  If an ink tank without a memory is used, the amount of light is detected through step S18 instead of step S16. If the amount of light is zero in step S19, the ink tank is considered to have been replaced. The written dot count value is reset, and the process returns to step S1. A flowchart in this case is shown in FIG.

  By doing so, it is possible to automatically reset the count value of the number of ink ejections and continue the ink remaining amount detection.

  Further, in the warning display processing in step S14, the recording operation may be controlled so as not to cause a recording failure reliably, or the remaining amount corresponding to the estimated value of the remaining amount of ink. The display may be performed on the LCD. In this way, more detailed ink remaining amount information can be given to the user.

  As described above, this embodiment has a remaining amount detection function of both the optical detection method and the dot count method, and is measured by dot count in order to solve the problem that optical detection is erroneously detected due to an external factor. If the integrated value of ink consumption is less than the specified threshold, the optical discrimination result indicating that there is no remaining ink in the first space is ignored only for the first time, and if it is determined that there is no ink by optical detection more than the specified number of times, Even if the ink consumption integrated value by counting is less than the threshold value, the optical detection determination result is prioritized.

  As described above, according to the present invention, when the remaining amount of ink in the ink tank is detected using a plurality of types of detection methods, the remaining amount of ink is equal to or greater than a predetermined amount by one of the detection methods for counting the amount of ink used. In general, the detection result by the detection method that counts the amount of ink used is given priority over the detection result by the other detection method that detects the ink amount (or the presence or absence of ink) in the ink tank. Detection that detects the amount of ink (or the presence or absence of ink) when the detection result of detecting the amount of ink in the tank (or the presence or absence of ink) has been reduced more than a predetermined number of times (or no ink) Prioritize detection results by method. According to the present invention, when the remaining amount of ink in the ink tank is detected using a plurality of types of detection methods, the remaining amount of ink is accurately detected even when the detection results obtained by the respective detection methods are different. It becomes possible.

  Although the embodiment described above has been described with an example using an optical sensor, the presence or absence of raw ink in the ink storage unit may be detected by other methods such as detection using an electrode. The type of detection system to be adopted should be determined from the overall viewpoint of performance and cost as the system of the ink jet recording apparatus. By adopting the optimum method, the cost can be reduced even with the same effect.

  For example, when the ink tank is already provided with a conductor portion that communicates with ink, the use of an electrode type detection system can be lower in cost than the provision of a new optical detection system.

  In the above embodiment, the liquid droplets ejected from the recording head have been described as ink, and the liquid stored in the ink tank has been described as ink. However, the storage is limited to ink. It is not a thing. For example, a treatment liquid discharged to the recording medium may be accommodated in the ink tank in order to improve the fixability and water resistance of the recorded image or to improve the image quality.

  The above embodiment includes means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used for performing ink discharge, particularly in the ink jet recording system, and the ink is generated by the thermal energy. By using a system that causes a change in the state of recording, it is possible to achieve higher recording density and higher definition.

  As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid, and as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. When this drive signal is in a pulse shape, the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve the discharge of liquid (ink) having particularly excellent responsiveness.

  As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.

  As the configuration of the recording head, in addition to the combination configuration (straight liquid flow path or right-angle liquid flow path) of the discharge port, the liquid path, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting surface The configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region, are also included in the present invention. In addition, Japanese Patent Application Laid-Open No. 59-123670, which discloses a configuration in which a common slot is used as a discharge portion of an electrothermal transducer, or an opening that absorbs a pressure wave of thermal energy is discharged to a plurality of electrothermal transducers. A configuration based on Japanese Patent Laid-Open No. 59-138461 disclosing a configuration corresponding to each part may be adopted.

  Furthermore, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is satisfied by a combination of a plurality of recording heads as disclosed in the above specification. Either a configuration or a configuration as a single recording head formed integrally may be used.

  In addition to the cartridge-type recording head in which the ink tank is integrally provided in the recording head itself described in the above embodiment, it can be electrically connected to the apparatus body by being attached to the apparatus body. A replaceable chip type recording head that can supply ink from the apparatus main body may be used.

  In addition, it is preferable to add recovery means, preliminary means, and the like for the recording head to the configuration of the recording apparatus described above because the recording operation can be further stabilized. Specific examples thereof include a capping unit for the recording head, a cleaning unit, a pressurizing or sucking unit, an electrothermal converter, a heating element different from this, or a preheating unit using a combination thereof. In addition, it is effective to provide a preliminary ejection mode for performing ejection different from recording in order to perform stable recording.

  Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrated or may be a combination of a plurality of colors. An apparatus having at least one of full colors can also be provided.

  In the embodiment described above, the description is made on the assumption that the ink is a liquid, but it may be an ink that is solidified at room temperature or lower, or an ink that is softened or liquefied at room temperature, Alternatively, the ink jet method generally controls the temperature of the ink so that the viscosity of the ink is within a stable discharge range by adjusting the temperature within a range of 30 ° C. or higher and 70 ° C. or lower. It is sufficient if the ink sometimes forms a liquid.

  In addition, it is solidified in an untreated state in order to actively utilize the temperature rise caused by thermal energy as energy for changing the state of the ink from the solid state to the liquid state, or to prevent ink evaporation. Ink that is liquefied by heating may be used. In any case, by applying heat energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case of using ink having the property of liquefying for the first time. In such a case, the ink is held as a liquid or solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260, It is good also as a form which opposes with respect to an electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.

  In addition, as a form of the recording apparatus according to the present invention, a copying apparatus combined with a reader or the like, and a transmission / reception function are provided as an image output terminal of an information processing apparatus such as a computer or the like. It may take the form of a facsimile machine.

  Note that the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), or an apparatus including a single device (for example, a copier, a facsimile machine, etc.). You may apply.

  Another object of the present invention is to supply a storage medium storing software program codes for implementing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in the.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is recorded in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board is based on the instruction of the program code. It goes without saying that the CPU of the function expansion unit or the like performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

It is a figure explaining the principle which detects the ink remaining amount in an ink tank using an optical sensor. It is a figure explaining the principle which detects the ink remaining amount in an ink tank using a reflection type sensor. 5 is a flowchart illustrating an outline of ink remaining amount detection processing. It is a flowchart which shows the ink remaining amount detection process at the time of replacing | exchanging with a new ink tank (in the case of an ink tank with a memory). It is a flowchart which shows the ink remaining amount detection process at the time of replacing | exchanging with a new ink tank (when it is not an ink tank with a memory). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view illustrating a schematic configuration of a recording apparatus including a recording head that performs recording in accordance with an inkjet method that is a representative embodiment of the present invention. 3 is a block diagram illustrating a configuration of a control circuit of the recording apparatus. FIG. 4 is a block diagram showing a detailed configuration of an ink remaining amount detection unit 25. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording head 2 Carriage 3 Guide shaft 4 Carriage motor 5 Timing belt 6 Engagement claw 7 Ink tank 8 Platen 9 Feed motor 10 Recovery apparatus 11 Cap 12 Wiper 13 ASF
DESCRIPTION OF SYMBOLS 14 Optical unit 15 Issuing element 16 Light receiving element 17 Chassis 20 Ink cartridge 25 Ink remaining amount detection part 28 Infrared light 29 Infrared light 30 LED drive circuit 31 Low-pass filter (LPF)
32 Controller 101 Ink tank 102 Ink supply port to recording head 103 Air communication port 104 Ink 105 Ink absorber 106 Partition plate 107 Raw ink 108 Light source (LED)
109 Photodetector 110 Nonvolatile memory 111 Light source 112 Photodetector 113 Lens 114 Irradiation light 115 Prism 116 Reflected light 1700 Interface 1701 MPU
1702 ROM
1703 DRAM
1704 Gate array 1705 Head driver 1706 Feed motor driver 1707 Carriage motor driver 1710 Display unit 1711 LCD
1712 LED lamp

Claims (20)

  Ink remaining amount in an ink tank having a first space for storing ink and a second space for storing an ink absorber that has absorbed the ink to supply to a recording head that performs recording in accordance with an inkjet method In the remaining ink amount detection method for detecting ink, there are at least two types of detection methods, and priority is given to the result of the first detection method up to a certain ink usage threshold, but the specified number of times when the ink usage is less than the threshold As described above, when the second detection method detects that there is no ink, priority is given to the result of the second detection method.   The ink remaining amount detection method according to claim 1, wherein the ink usage amount threshold is the same or different depending on a type of ink.   The ink remaining amount detection method according to claim 1, wherein the specified number of times is two or more.   2. The ink remaining amount detection method according to claim 1, wherein the first detection method is a dot count method, and the second detection method is an optical detection method.   In the optical detection method, light is incident on the first space, reflected light or transmitted light of the light is detected, and remaining ink in the first space is detected based on the detected light. The ink remaining amount detection method according to claim 4, further comprising a determination step of determining presence or absence of ink.   The dot counting method includes a counting step for counting the number of ink ejections from the recording head, and the number of ink ejections counted in the counting step until it is determined in the determination step that there is no remaining ink in the first space. A step of integrating the integrated value and the threshold value, and determining whether there is no remaining ink in the first space if the integrated value is equal to or greater than the threshold value, and remaining ink in the determining step After determining that there is no ink, the integration step of integrating the number of ink discharges in the second space and the number of ink discharges in the second space are compared with a specified threshold value to compare the remaining amount of ink in the ink tank. The method for detecting the remaining amount of ink according to claim 4, further comprising a determination step of determining presence or absence.   The ink remaining amount detection method according to claim 6, wherein the prescribed threshold value of the number of ejections in the second space is the same or different depending on the type of ink.   2. The ink remaining amount detection method according to claim 1, wherein the determination step result and the determination step result are recorded in a memory associated with an ink tank or a main body memory.   In the determination step, the number of times of optical detection determination is one and the ink usage integrated value by dot count is less than the threshold value, or the remaining amount of ink in the first space recorded in the memory associated with the ink tank or the main body memory is zero. 2. The ink remaining amount detection method according to claim 1, wherein if the determination result in the determination step indicates that there is no ink, the optical detection determination result indicating no ink is rejected.   When the determination result of the predetermined number of executions of the determination step indicates that there is no ink, the integrated amount of ink used by the dot count is less than the threshold value, or the first space recorded in the memory associated with the ink tank or the main body memory. 2. The ink remaining amount detection method according to claim 1, wherein when the ink remaining amount is not zero, priority is given to the optical detection determination result without ink.   Ink remaining amount in an ink tank having a first space for storing ink and a second space for storing an ink absorber that has absorbed the ink to supply to a recording head that performs recording in accordance with an inkjet method In the remaining ink amount detection method for detecting ink, there are at least two types of detection methods, and priority is given to the result of the first detection method up to a certain ink usage threshold, but the specified number of times when the ink usage is less than the threshold An ink jet recording apparatus characterized in that priority is given to the result of the second detection method when no ink is detected in the second detection method.   The inkjet recording apparatus according to claim 11, wherein the threshold of the ink usage amount is the same or different depending on a type of ink.   The inkjet recording apparatus according to claim 11, wherein the specified number of times is two or more.   The inkjet recording apparatus according to claim 11, wherein the first detection method is a dot count method, and the second detection method is an optical detection method.   In the optical detection method, light is incident on the first space, reflected light or transmitted light of the light is detected, and remaining ink in the first space is detected based on the detected light. The inkjet recording apparatus according to claim 14, further comprising a determination step of determining presence or absence of the ink.   The dot counting method includes a counting step for counting the number of ink ejections from the recording head, and the number of ink ejections counted in the counting step until it is determined in the determination step that there is no remaining ink in the first space. A step of integrating the integrated value and the threshold value, and determining whether there is no remaining ink in the first space if the integrated value is equal to or greater than the threshold value, and remaining ink in the determining step After determining that there is no ink, the integration step of integrating the number of ink discharges in the second space and the number of ink discharges in the second space are compared with a specified threshold value to compare the remaining amount of ink in the ink tank. The inkjet recording apparatus according to claim 14, further comprising a determination step of determining presence or absence.   The inkjet recording apparatus according to claim 16, wherein the prescribed threshold value of the number of ejections in the second space is the same or different depending on the type of ink.   The inkjet recording apparatus according to claim 11, wherein the determination process result and the determination process result are recorded in a memory associated with an ink tank.   In the determination step, the number of times of optical detection determination is one and the ink usage integrated value by dot count is less than the threshold value, or the remaining amount of ink in the first space recorded in the memory associated with the ink tank or the main body memory is zero. The inkjet recording apparatus according to claim 11, wherein if the determination result of the determination step indicates that there is no ink, the optical detection determination result indicating no ink is rejected.   When the determination result of the predetermined number of executions of the determination step indicates that there is no ink, the integrated amount of ink used by the dot count is less than the threshold value, or the first space recorded in the memory associated with the ink tank or the main body memory. 12. The ink jet recording apparatus according to claim 11, wherein when the remaining amount of ink is not zero, priority is given to the optical detection determination result without ink.

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