JPH04220353A - Method for detecting residual quantity of ink - Google Patents

Abstract

PURPOSE:To achieve high reliability in detecting a residual quantity of ink by a method wherein a recording head which performs recording by spraying ink and a pressure sensor located in an ink reservoir for feeding ink to the record head or in an ink passage leading from the recording head to the ink reservoir are provided in an ink jet recording device to detect the residual quantity of ink in the ink reservoir by measuring pressure changes by means of the pressure sensor. CONSTITUTION:After starting a recording operation of a recording head, an operation for detecting a residual quantity of ink is started when the recording operation has been completed.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for detecting the amount of ink remaining in an inkjet recording device, and particularly relates to a method for detecting the amount of ink remaining in an inkjet recording device, and in particular,
For inkjet recording devices that are equipped with a pressure sensor in a print head that performs printing, an ink reservoir that supplies ink to the print head, or an ink path leading from the print head to the ink reservoir, there is no residual ink in the ink reservoir. The present invention relates to a method for detecting the remaining amount of ink by detecting the amount based on a pressure change measured by the pressure sensor.

0002

2. Description of the Related Art Conventionally, jet recording apparatuses include a jet recording apparatus according to a first conventional example of a type in which ink is replenished into an ink reservoir 2 shown in FIG. 13, which corresponds to a first conventional example; There is a jet recording apparatus B according to a second conventional example in which an ink cartridge 3 is replaced as an ink reservoir. Both have a recording head 1,
In the jet recording apparatus according to the second conventional example, an ink supply tube 4 for supplying ink to the recording head 1 is provided between the ink cartridge 3 and the recording head 1. Conventionally, the remaining amount of ink has been detected in or near the ink reservoir of each jet recording device. In order to detect the remaining amount of ink, in the first conventional example, electrodes 21 and 22 are provided inside the ink reservoir 2, as shown in FIG. The remaining amount of ink is detected by this detection. Furthermore, in the second conventional example, as shown in FIG. The plate 14 is brought into elastic contact with the pack 16, and the displacement of the plate 14 is detected by an optical sensor 15. When the ink runs out, the ink supply to the ink recording head is interrupted, making it impossible to eject ink droplets. Ink ejection stops when the ink in the head runs out, and does not necessarily coincide with when the ink reservoir runs out of ink. Therefore, in order to prevent ink ejection from stopping, it is necessary to issue an ink empty signal fairly early. Therefore,
A considerable amount of ink that is not used for recording remains in the ink reservoir, resulting in a lot of waste. Furthermore, inks from different production lots mix with each other, resulting in a decrease in reliability. In either case, the remaining amount of ink increases. When the amount of ink decreases, ink was previously supplied into the head (nozzle part) by capillary force, but due to the height of the liquid level and the nozzle part, the negative pressure becomes large and sufficient supply is no longer possible. Therefore, since the ink is replenished while there is a large amount of ink remaining, a considerable amount of old and new ink will be mixed together, which is not desirable in terms of reliability. Further, in device B as well, since the cartridge needs to be replaced early, a considerable amount of ink is wasted.

In response to this problem, the present inventor has proposed a method in which the pressure inside the ink passage is detected by a pressure sensor provided in the ink passage, and when the pressure falls below a predetermined pressure, the ink empty is detected. A specific example of this method is shown in FIGS. 11 and 12. What is shown in FIG. 11 is a jet recording apparatus according to the first conventional example described above, in which a pressure sensor 5 is provided, and the pressure detected by the pressure sensor 5 is detected by an ink remaining amount detection control section 6. It is. Furthermore, the jet recording apparatus shown in FIG. 12 is a second conventional example, in which a pressure sensor 5 for detecting the pressure inside the ink supply tube 4 is provided, and the detected pressure is sent to an ink remaining amount detection control section. 6.

0004

[Problems to be Solved by the Invention] By the way, in the method proposed by the present inventor in which the remaining amount is detected by using a pressure sensor to detect the pressure in the ink passage, the pressure sensor is capable of detecting fluctuations in the pressure in the ink passage due to a decrease in the remaining amount of ink. Furthermore, in the case of a serial printer, pressure fluctuations due to head scanning are also detected, which has the problem of lowering the reliability of ink remaining amount detection.

[0005] Therefore, the present invention has been made with the aim of improving the reliability of detecting the remaining amount of ink, and stipulates the timing of detecting the remaining ink amount while avoiding fluctuations in the pressure inside the ink passage due to recording operations. This was done with the aim of increasing the reliability of detecting the amount of remaining ink.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned technical problems, the first invention, as shown in FIG. For an inkjet recording device in which a pressure sensor is provided in an ink reservoir to be supplied or an ink passage leading from a recording head to an ink reservoir, the amount of ink remaining in the ink reservoir is detected based on pressure changes measured by the pressure sensor. In the remaining amount detection method, after a printing operation by the print head is started (S1), and when the printing operation is finished (S2), an operation for detecting the remaining amount of ink is performed (
S3) It is something.

[0007]

[Operation] In the present invention, after the recording operation by the recording head is started in step S1, and the recording operation is finished in step S2, the remaining amount of ink in the ink reservoir is measured by a pressure sensor in step S3. By doing so, the remaining ink amount detection operation is performed. This is because if pressure is detected during the recording operation to detect the remaining amount of ink, the amount of remaining ink cannot be accurately detected due to fluctuations in the ink pressure due to the recording operation. 2 shows a first embodiment of the invention, FIG. 3 shows a second embodiment of the invention, and FIG. 4 shows a third embodiment of the invention.

[0008]

[Example] Next, an example of the present invention will be described. 11 and 12 show a jet recording apparatus according to this embodiment. The apparatus shown in FIG. 11 includes a recording head 1, an ink reservoir 2, a pressure sensor 5 that detects the pressure of ink stored in the ink reservoir 2, and a pressure sensor 5 that detects the pressure of ink stored in the ink reservoir 2.
The remaining ink amount detection control section 6 detects the remaining amount of ink based on the pressure detected by the pressure detected by the pressure sensor. Further, the apparatus shown in FIG. 12 includes a recording head 1, an ink cartridge 3, an ink supply tube 4 that connects the recording head 1 and the ink cartridge 3, and supplies ink to the recording head 1. It has a pressure sensor 5 that detects the pressure of flowing ink, and an ink detection control section 6 that detects the remaining amount of ink based on the detected pressure.

Next, the operation of detecting the remaining amount of ink according to this embodiment will be explained. The operation according to the first embodiment will be explained with reference to FIG. As shown in the figure, step SJ1
Then, it is determined whether or not to put the jet recording device into a standby state waiting for input of recording data. If the jet recording apparatus is to be placed in a standby state, the jet recording apparatus is placed in a standby state in step SJ2, and if recording data is input in step SJ3, the process proceeds to step SJ4, where the recording head 1 starts a recording operation, and the process proceeds to step SJ2. Continuing the recording operation in SJ5, continuing the above operations until all the recorded data is completed in step SJ6, and when the recording operation ends in step SJ7, proceeding to step SJ8 and starting the operation of detecting the remaining amount of ink. become. On the other hand, if no recording data is input in step SJ3, the process returns to step SJ1 again. The remaining amount of ink is detected in step SJ81, in which the pressure sensor 5 detects the pressure of the ink in the ink reservoir 2 or the ink supply tube 4, and the remaining ink amount detection control section 6 detects the remaining amount of ink. This is done through detection. In step SJ82, if there is still ink remaining, the process returns to step SJ1 again, and it is determined whether to enter a standby state for inputting print data. If it is determined that there is no ink remaining, step S
The process advances to J83, where an ink empty message is displayed to prompt the operator to replenish ink.

FIG. 6 shows the operation of the second embodiment. As shown in the figure, it is determined in step SJ1 whether or not the jet recording device should be placed in a standby state waiting for input of print data, and if the jet printing device is placed in a standby state, the process proceeds to step SJ31, where the remaining ink amount detection control unit Then, a predetermined decay time T0 of pressure fluctuation within the ink passage due to ink consumption due to printing is input. If recording data is input in step SJ3, the process advances to step SJ4, where the recording operation is started,
The recording operation is continued until all of the input recording data is completed, and when all the recording operations are completed in step SJ7, the process proceeds to step SJ32, and measurement of the elapsed time T is started from the point at which the recording operation is completed. If it is confirmed in step SJ32 that the time measured has exceeded the set time T0, the process proceeds to step SJ8, where an operation for detecting the remaining amount of ink is performed. Compared to the first embodiment, this embodiment eliminates the influence of pressure fluctuations in the ink passage due to ink consumption due to recording when measuring pressure in the remaining amount detection operation, resulting in improved reliability.

Next, FIG. 7 shows the operation according to the third embodiment. As shown in the figure, in step SJ1, it is determined whether or not to put the jet recording device into a standby state waiting for input of recording data, and if the jet recording device is put into a standby state, the process advances to step SJ34, and the pressure decay time T0 and If you want to detect the remaining amount of ink during the recording operation, set the time interval to the predetermined recording time t.
Enter it as 0. After starting the recording operation in step SJ4, in step SJ35 the time during which the recording operation was performed from the recording start point is measured (steps SJ36, SJ37), and in step SJ38, if the measured time t exceeds the predetermined time t0, The process advances to step SJ7, and the recording operation is ended at that point. Thereafter, the process proceeds to ink detection operation step SJ8. Therefore, according to this embodiment, it is possible to prevent printing from being stopped due to ink shortage during printing. Furthermore, in this embodiment, as shown in FIG. 7, before entering the ink detection operation in step SJ8, step SJ391 of step SJ39
Then, the elapsed time T after the end of the recording operation is measured, and step S
Compare the measurement time with the preset To in J392,
When the time has elapsed, the process proceeds to step SJ8 for performing the ink detection operation described above. Therefore, when measuring the pressure in the remaining amount detection operation, by measuring the time from the start of the recording operation to measure the pressure fluctuation in the ink passage due to ink consumption due to recording, the pressure inside the ink passage due to ink consumption due to recording can be measured. Since the influence of fluctuations is eliminated, reliability can be further improved. Further, FIGS. 8, 9, and 10 show the case of a serial printer that performs printing by scanning the print head.

FIG. 8 shows the operation of the fourth embodiment. In step SJ1, it is determined whether or not the jet recording apparatus is to be put into a standby state. If it is determined to be put into a standby state, the process proceeds to step SJ2, and the jet recording apparatus is put into a standby state waiting for input of recording data. If recording data is input in step SJ3, the process advances to step SJ40, where head scanning is started, and then the process advances to step SJ4, where a recording operation is started. If the recording of all recorded data is completed in step SJ7, step SJ4
1, and head scanning is also completed. After the head scan is completed, the remaining ink amount detection operation begins in step SJ8.

FIG. 9 shows the operation according to the fifth embodiment. In this embodiment, a decay time T1 of pressure fluctuations in the ink passage due to head scanning is set in advance, and when print data is input, the head scans and prints until there is no more data. Recording ends when the data ends, and head scanning ends in step SJ41. Step SJ4
Step 3 measures the elapsed time T from this point and refers to the time T. After confirming that T exceeds the pressure decay time T1 in step SJ44, the remaining ink amount detection operation is performed. Compared to the fourth embodiment shown in FIG. 8, when measuring the pressure in the remaining amount detection operation, the influence of pressure fluctuations in the ink passage due to head scanning is eliminated, and reliability is improved.

FIG. 10 shows the operation of the sixth embodiment. In this embodiment, the pressure decay time T1 and the time interval when it is desired to detect the remaining amount of ink during the recording operation are input as the predetermined recording time t0. The time t from the start of the recording operation is measured and referenced, and the predetermined time t0 is
The recording operation is ended when the value exceeds (step SJ7).
. After that, when the head reaches the scanning reversal position, head scanning is finished and the head is stopped (step SJ42).
, enters the remaining ink level detection operation. This prevents printing from being stopped due to ink shortage during printing. In addition, by adding the operation shown in the frame in the figure (step SJ45), when measuring pressure in the remaining amount detection operation,
This eliminates the influence of pressure fluctuations in the ink passage due to head scanning, and further improves reliability.

[0015]

As described above, in the present invention, the operation of detecting the remaining amount of ink is performed at the time when the recording operation is completed. Therefore, fluctuations in ink pressure during recording do not affect the pressure detection result when detecting the remaining amount of ink, and the remaining amount of ink can be detected reliably.

[Brief explanation of the drawing]

[Figure 1] Principle block diagram of the invention

[Fig. 2] Diagram showing the first embodiment of the invention

[Fig. 3] A diagram showing a second embodiment of the invention.

[Fig. 4] A diagram showing a third embodiment of the invention.

[Figure 5] Flowchart according to the first embodiment

[Fig. 6] Flowchart according to the second embodiment

[Figure 7] Flowchart according to the third embodiment

[Fig. 8] Flowchart according to the fourth embodiment

[Figure 9] Flowchart according to the fifth embodiment

[Fig. 10] Flowchart according to the sixth embodiment

FIG. 11 is a diagram showing a recording device having a remaining ink amount detection means according to an embodiment.

FIG. 12 is a diagram showing a recording apparatus having a remaining ink amount detection means according to another embodiment.

FIG. 13 is a diagram showing an inkjet recording device according to a first conventional example.

FIG. 14 is a diagram showing an inkjet recording device according to a second conventional example.

FIG. 15 is a diagram showing the remaining ink amount detection means according to the first conventional example.

FIG. 16 is a diagram showing a remaining ink amount detection means according to a second conventional example.

[Explanation of symbols]

1 Recording head 2 Ink reservoir 3 Ink cartridge 5 Pressure sensor

Claims (6)

[Claims] 1. An inkjet recording device that includes a recording head that ejects ink to perform recording, an ink reservoir that supplies ink to the recording head, or a pressure sensor in an ink passage from the recording head to the ink reservoir. In the remaining ink amount detection method of detecting the remaining amount of ink in the ink reservoir based on a pressure change measured by the pressure sensor, when the printing operation is finished after the printing operation by the printing head has started (S1). The remaining ink amount detection method is characterized in that (S2), a remaining ink amount detection operation is performed (S3). [Claim 2] An inkjet recording device that includes a recording head that ejects ink to perform recording, an ink reservoir that supplies ink to the recording head, or a pressure sensor in an ink passage from the recording head to the ink reservoir. , in the remaining ink amount detection method of detecting the remaining amount of ink in the ink reservoir based on a change in the pressure inside the passage measured by the pressure sensor, after starting the printing operation by the printing head (S1), the printing operation ends. In the case (S2),
2. The method for detecting the remaining amount of ink according to claim 1, wherein the method is carried out at a time point (S5) when fluctuations in the pressure in the ink passage due to the recording operation have attenuated after the recording operation is completed. 3. An inkjet recording device that includes a recording head that ejects ink to perform recording, an ink reservoir that supplies ink to the recording head, or a pressure sensor in an ink passage from the recording head to the ink reservoir. In the remaining ink amount detection method of detecting the remaining amount of ink in the ink reservoir based on the pressure change measured by the pressure sensor, after starting the printing operation by the print head (S
1). It is determined whether the recording operation has ended (S6), and if the recording operation has not ended yet, it is determined whether a predetermined time has elapsed, and if the predetermined time has ended or the recording operation has ended. In this case, the recording operation is interrupted or terminated (S2), and the remaining ink amount is detected after the recording operation is completed (S3). 4. A serial printer comprising: a print head that ejects ink while scanning and performs printing; and an ink reservoir that supplies ink to the print head; or a pressure sensor provided in an ink passage from the print head to the ink reservoir. Regarding an inkjet recording device, in the ink remaining amount detection method of detecting the remaining amount of ink in the ink reservoir based on the pressure change measured by the pressure sensor, after starting the recording operation by the recording head (S1), After completing the scanning (S8), the remaining amount of ink is detected (S3).
) The remaining ink amount detection method according to claim 1. 5. A serial printer comprising: a printhead that ejects ink while scanning and performs printing; and an ink reservoir that supplies ink to the printhead; or a pressure sensor in an ink passage from the printhead to the ink reservoir. Regarding an inkjet recording device, in an ink remaining amount detection method that detects the amount of ink remaining in the ink reservoir based on pressure changes measured by the pressure sensor, the remaining ink amount detection operation is performed by head scanning to detect changes in the pressure inside the ink passage. 5. The method of detecting remaining ink amount according to claim 4, wherein the ink level detection method is carried out at a time point when the amount of ink is attenuated. 6. A serial printer comprising: a printhead that ejects ink while scanning and performs printing; and an ink reservoir that supplies ink to the printhead; or a pressure sensor in an ink passage from the printhead to the ink reservoir. Regarding inkjet recording devices, in the ink remaining amount detection method that detects the amount of ink remaining in the ink reservoir based on the pressure change measured by the pressure sensor, after a predetermined recording time has elapsed, the amount of ink remaining in the ink reservoir is detected when the head stops during head scanning reversal. 6. The method for detecting the amount of remaining ink according to claim 4, further comprising detecting the amount of ink.