A nozzle detection system and a nozzle detection method

Abstract

The present invention discloses a nozzle detection system and a nozzle detection method, which relate to the field of inkjet printing technology, in order to solve the problems of high cost and low efficiency of nozzle detection in the prior art. The system comprises: a light source and a photodetector; the light source comprises a light emitting diode; the photodetector comprises at least a photosensitive diode, a first integral amplifier circuit and a second integral amplifier circuit; the photosensitive diode is used to collect the light intensity information of at least one nozzle after ink is dripped in the illuminated area formed by the light emission of the light source, and convert the light intensity information into a first electrical signal in the first round of nozzle detection or a second electrical signal in the second round of nozzle detection; the first integral amplifier circuit amplifies the third electrical signal to obtain a first amplified signal or amplifies the fourth electrical signal to obtain a second amplified signal; the second integral amplifier circuit amplifies the second amplified signal to obtain a third amplified signal; the system obtains the nozzle detection result based on the first amplified signal and the third amplified signal.

Description

Technical Field

[0001] The present invention relates to the technical field of inkjet printing, and in particular to a nozzle detection system and a nozzle detection method. Background Art

[0002] After the inkjet printer has been working for a certain period of time, the nozzles on the nozzles may be clogged. The reasons may be ink path pollution, ink precipitation, dust, water vapor, etc. The clogged nozzles will cause abnormal ink ejection volume and ink ejection rate, thus affecting the printing quality. In order to improve the printing quality, the nozzles need to be tested.

[0003] The existing method of checking nozzle blockage is to print some images on the substrate, use the naked eye to determine whether there is blockage, and then decide whether to clean it. This process requires human participation, which consumes manpower costs, and for special printing materials (such as colorless solutions), human judgment is particularly difficult.

[0004] How to reduce the cost of nozzle inspection and improve the inspection efficiency has become an urgent problem to be solved in this field. Summary of the invention

[0005] The object of the present invention is to provide a nozzle detection system and a nozzle detection method, which are used to reduce the nozzle detection cost and improve the detection efficiency.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a nozzle detection system, comprising:

[0008] A light source and a photodetector; the light source comprises at least one light emitting diode; the light source is arranged opposite to the photodetector;

[0009] The photodetector at least comprises a photosensitive diode, a first integral amplifier circuit and a second integral amplifier circuit;

[0010] The output end of the first integral amplifier circuit is connected to the input end of the second integral amplifier circuit;

[0011] The photosensitive diode is used to collect light intensity information of at least one nozzle after ink is dropped in the illuminated area formed by the light source, and convert the light intensity information in the first round of nozzle detection into a first electrical signal, or convert the light intensity information in the second round of nozzle detection into a second electrical signal;

[0012] The first integral amplifier circuit is used to amplify a third electrical signal corresponding to the first electrical signal to obtain a first amplified signal; the first integral amplifier circuit is also used to amplify a fourth electrical signal corresponding to the second electrical signal to obtain a second amplified signal;

[0013] The first electrical signal and the second electrical signal are both analog current signals, and the third electrical signal and the fourth electrical signal are both analog voltage signals;

[0014] The second integral amplifier circuit is used to amplify the second amplified signal to obtain a third amplified signal;

[0015] The nozzle detection system obtains a nozzle detection result based on the first amplified signal and the third amplified signal.

[0016] Optionally, the photodetector further includes a VI conversion circuit and a peak detection circuit;

[0017] The photosensitive diode is connected to the VI conversion circuit; the input end of the first integral amplifier circuit is connected to the output end of the VI conversion circuit; the input end of the peak detection circuit is connected to the output end of the first integral amplifier circuit;

[0018] The VI conversion circuit is used to convert the first electrical signal into the third electrical signal; the VI conversion circuit is also used to convert the second electrical signal into the fourth electrical signal;

[0019] The peak detection circuit is used to accumulate a preset number of first amplified signals to obtain a first electrical signal to be detected;

[0020] The nozzle detection system is used to determine an abnormal nozzle group based on the first electrical signal to be detected.

[0021] Optionally, the photodetector further comprises a first waveform shaping circuit; the input end of the first waveform shaping circuit is connected to the output end of the second integral amplifier circuit;

[0022] The first waveform shaping circuit is used to perform analog-to-digital conversion on the third amplified signal to obtain a second signal to be detected; the second signal to be detected is a digital signal;

[0023] The nozzle hole detection system is further used to determine an abnormal nozzle hole based on the second signal to be detected.

[0024] Optionally, the photodetector further includes a light path detection circuit; the input end of the light path detection circuit is connected to the output end of the VI conversion circuit; the light path detection circuit is used to monitor the path condition of the photodetector.

[0025] Optionally, the optical path detection circuit includes an amplification circuit and a second waveform shaping circuit;

[0026] The input end of the amplifier circuit is the input end of the optical path detection circuit, and the output end of the amplifier circuit is connected to the input end of the second waveform shaping circuit;

[0027] The amplifier circuit is used to amplify the third electrical signal or the fourth electrical signal to obtain a fourth amplified signal;

[0028] The second waveform shaping circuit is used to perform analog-to-digital conversion on the fourth amplified signal to obtain a third signal to be detected; the third signal to be detected is a digital signal;

[0029] The nozzle detection system is also used to confirm whether the photoelectric detector works normally based on the third signal to be detected.

[0030] In a second aspect, the present invention further provides a nozzle detection method, which is applied to a nozzle detection system; the nozzle detection system comprises a light source and a photodetector; the light source comprises at least one light emitting diode; the light source and the photodetector are arranged opposite to each other; the photodetector comprises at least a photosensitive diode, a first integral amplifier circuit and a second integral amplifier circuit;

[0031] The nozzle detection method comprises:

[0032] The nozzle detection system receives a first electrical signal in a first round of nozzle detection;

[0033] Sending a third electrical signal corresponding to the first electrical signal to the first integrating amplifier circuit;

[0034] receiving a first amplified signal obtained after the first integral amplifier circuit amplifies the third electrical signal;

[0035] Receive a second electrical signal in the second round of nozzle detection; wherein the first electrical signal and the second electrical signal are both acquired by the photodiode collecting light intensity information after at least one nozzle drips ink in the illuminated area formed by the light source, and the light intensity information is converted;

[0036] sending a fourth electrical signal corresponding to the second electrical signal to the first integral amplifier circuit; the first integral amplifier circuit is used to amplify the fourth electrical signal to obtain a second amplified signal; the first electrical signal and the second electrical signal are both analog current signals, and the third electrical signal and the fourth electrical signal are both analog voltage signals;

[0037] sending the second amplified signal to the second integrating amplifier circuit;

[0038] receiving a third amplified signal obtained after the second amplified signal is amplified by the second integral amplifier circuit;

[0039] A nozzle hole detection result is obtained based on the first amplified signal and the third amplified signal.

[0040] Optionally, obtaining a nozzle detection result based on the first amplified signal and the third amplified signal includes:

[0041] determining an abnormal nozzle group based on the first amplified signal;

[0042] After the abnormal nozzle group is obtained, the abnormal nozzle is determined based on the third amplified signal.

[0043] Optionally, before the nozzle detection system receives the first electrical signal, the method further includes:

[0044] Controlling the light source to emit light;

[0045] Controlling each column of nozzles in the plurality of nozzles to move to the illumination area along a first moving direction in sequence; the first moving direction is perpendicular to the column direction of the nozzles;

[0046] Controlling all nozzles in each group of nozzles in each column of nozzles to perform a continuous ink drop step in the illuminated area in order; wherein each group of nozzles includes a plurality of nozzles; the photosensitive diode collects first light intensity information after the plurality of nozzles continuously drop ink in the illuminated area, and converts the first light intensity information into the first electrical signal;

[0047] Alternatively, before the nozzle detection system receives the second electrical signal, the method further includes:

[0048] After each column of nozzles completes the continuous ink dripping step, all nozzles in each abnormal nozzle group in each column of nozzles are controlled to drip ink one by one; wherein the photosensitive diode collects the second light intensity information of each nozzle after dripping ink in the illuminated area, and converts the second light intensity information into the second electrical signal.

[0049] Optionally, if the accumulated voltage value corresponding to the first amplified signal is less than a first preset value, the nozzle group corresponding to the first amplified signal is determined as the abnormal nozzle group;

[0050] The determining of the abnormal nozzle based on the third amplified signal comprises:

[0051] If the voltage value corresponding to the third amplified signal is less than the second preset value, the nozzle corresponding to the third amplified signal is determined as the abnormal nozzle.

[0052] Optionally, the nozzle detection system uses PWM technology to control the light source to emit light; the nozzle detection system controls the duty cycle based on ink drop color information.

[0053] Compared with the prior art, the present invention provides a nozzle detection system and a nozzle detection method. When performing nozzle detection on at least one nozzle in an inkjet printing device, a light source is arranged opposite to the photodetector, the light source emits light to form an illumination area, and the nozzle detection system controls, for example, a certain column of nozzles in the nozzle to move to the illumination area. The first integral amplifier circuit and the second integral amplifier circuit can be used to perform two rounds of detection on each column of nozzles. In the first round of nozzle detection, all nozzles in each group of nozzles in each column of nozzles are controlled to drip ink continuously, and the photosensitive diode collects the first light intensity information of all nozzles after dripping ink in the illumination area formed by the light emission of the light source, and converts the first light intensity information into a first electrical signal. The first integral amplifier circuit converts the first electrical signal into a The corresponding third electrical signal is processed to finally obtain the first amplified signal, and the nozzle detection system determines the abnormal nozzle group according to the first amplified signal; in the second round of nozzle detection, all nozzles in each abnormal nozzle group in each column of nozzles are controlled to drop ink one by one, and the photosensitive diode collects the second light intensity information of a nozzle after dropping ink in the illumination area formed by the light source, and converts the second light intensity information into the corresponding second electrical signal, and sends the fourth electrical signal corresponding to the second electrical signal to the first integral amplifier circuit for processing. After the first integral amplifier circuit processes, the second amplified signal is obtained, and then sent to the second integral amplifier for processing, and finally the third amplified signal is obtained. The nozzle detection system determines the abnormal nozzle according to the third amplified signal. In this way, there is no need to detect the nozzles one by one, which greatly reduces the detection time and improves the detection efficiency. In addition, the light source uses light-emitting diodes instead of laser devices, which not only reduces the cost, but also because the illumination range of light-emitting diodes is larger than that of lasers, even if the position of each column of nozzles deviates slightly when the nozzle is controlled to move column by column, it can be detected, thereby improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0055] Figure 1 A schematic diagram of the structure of a nozzle detection system provided by an embodiment of the present invention;

[0056] Figure 2 A schematic diagram of a transmission angle and a receiving angle provided for an embodiment of the present invention;

[0057] Figure 3A schematic diagram of multiple nozzles to be inspected provided by one embodiment of the present invention;

[0058] Figure 4 One of the state schematic diagrams of the nozzle detection process provided by one embodiment of the present invention;

[0059] Figure 5 A second state diagram of a nozzle detection process provided by an embodiment of the present invention;

[0060] Figure 6 A schematic flow chart of a nozzle hole detection method provided in one embodiment of the present invention.

[0061] Reference numerals:

[0062] 10-light emitting diode; 20-photodetector; 21-photosensitive diode; 22-first integral amplifier circuit; 23-second integral amplifier circuit; 24-VI conversion circuit; 25-peak detection circuit; 26-first waveform shaping circuit; 27-amplifier circuit; 28-second waveform shaping circuit; 30-first group of nozzles; 31-last group of nozzles. DETAILED DESCRIPTION

[0063] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0064] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0065] In the present invention, "at least one" means one or more, "more than one" means two or more. "And / or" describes the association relationship of the associated objects, indicating that three types of relationships may exist.

[0066] like Figure 1 As shown, an embodiment of the present invention provides a nozzle detection system, which may include:

[0067] A light source and a photodetector 20; the light source comprises at least one light emitting diode 10; the light source and the photodetector are arranged opposite to each other;

[0068] The photodetector at least comprises a photosensitive diode 21, a first integral amplifier circuit 22 and a second integral amplifier circuit 23;

[0069] The output end of the first integral amplifier circuit 22 is connected to the input end of the second integral amplifier circuit 23;

[0070] The photodiode 21 is used to collect light intensity information of at least one nozzle after ink is dropped in the illuminated area formed by the light source, and convert the light intensity information in the first round of nozzle detection into a first electrical signal, or convert the light intensity information in the second round of nozzle detection into a second electrical signal;

[0071] The first integral amplifier circuit 22 is used to amplify the third electrical signal corresponding to the first electrical signal to obtain a first amplified signal; the first integral amplifier circuit 22 is also used to amplify the fourth electrical signal corresponding to the second electrical signal to obtain a second amplified signal;

[0072] The first electrical signal and the second electrical signal are both analog current signals, and the third electrical signal and the fourth electrical signal are both analog voltage signals;

[0073] The second integral amplifier circuit 23 is used for amplifying the second amplified signal to obtain a third amplified signal;

[0074] The nozzle detection system obtains a nozzle detection result based on the first amplified signal and the third amplified signal.

[0075] Specifically, the light source is arranged opposite to the photodetector 20, and the light source emits light to form an illumination area.

[0076] Optionally, the light in the light emitting diode 10 may be invisible light, such as infrared light. Because visible light is easily affected by other light in the printing environment, invisible light is not easily affected by other light, and other light may be natural light, etc. In this embodiment, invisible light is used to reduce the influence of other light, thereby improving the accuracy of the nozzle detection system.

[0077] The selection method of the emission angle of the light emitting diode 10 can be as follows: if the emission angle of the light emitting diode is too large, the light will not be very directional, thereby reducing the light intensity, and then reducing the sensitivity and accuracy of the detection; if the emission angle of the light emitting diode is too small, the range of light that can be detected will be narrow, thereby increasing the difficulty of detecting the light. After many experiments, the range of the emission angle is set to be selectable between the interval [5, 100] degrees, and good test results can be achieved. In some scenes of the prior art, lasers are selected as light source emission devices because lasers have strong penetrating power. However, in the scene of the nozzle bad hole detection of this embodiment, the light emitting diode 10 can be selected as the light source emission device. Its emission angle is larger than the laser emission angle in the laser device of the prior art, and the irradiation area of ​​the light source is also larger at the same distance from the receiving device. Therefore, under the same receiving device, the receiver can detect a wider range of light, thereby having better detection accuracy and detection efficiency than the laser device. For example, in this embodiment, the device model of the light emitting diode 10 can be SFH4550, and the device model of the photosensitive diode 21 can be PD333-3B.

[0078] In an optional implementation, the emission angle of the light emitting diode 10 is set to be different from the receiving angle of the photosensitive diode 21. Figure 2 As shown, when the distance between the light-emitting diode 10 and the photosensitive diode 21 is controlled to be the same, the first detection range when the emission angle of the light-emitting diode 10 and the receiving angle of the photosensitive diode 21 are both 6 degrees is compared with the second detection range when the emission angle of the light-emitting diode 10 is 6 degrees and the receiving angle of the photosensitive diode 21 is 40 degrees. It can be obtained that the first detection range is smaller than the second detection range. It can be seen from the figure that when the emission angle of the light-emitting diode 10 and the receiving angle of the photosensitive diode 21 are different, a larger detection range can be obtained, and when the difference between the emission angle and the receiving angle is greater, the detection range is larger and the alignment difficulty is smaller. On the basis of the above implementation, the emission angle of the light-emitting diode 10 can be set to be smaller than the receiving angle of the photosensitive diode 21. The reason for this setting is that selecting a light-emitting diode with a small emission angle usually makes the energy of the light more concentrated, the light intensity is greater, and the detection accuracy is improved; selecting a light-emitting diode with a large receiving angle can achieve the expansion of the detection range while reducing the misjudgment rate and alignment difficulty of broken hole detection. Therefore, the emission angle can be set to be greater than the receiving angle.

[0079] As mentioned above, the efficiency of the method of using a laser detection device to detect the nozzles one by one still needs to be improved, and the cost of using a laser device for detection is relatively high.

[0080] First, in order to solve the problem of low detection efficiency caused by detecting the nozzles one by one, one of the concepts of the present invention is: divide multiple nozzles (for example, 5 nozzles) in a row of nozzles or a column of nozzles in a nozzle head into a group, and perform the following operations for each row of nozzles or each column of nozzles: first perform the first round of nozzle detection, that is, the third electrical signal corresponding to the first electrical signal can be amplified by the first integral amplifier circuit to obtain the first amplified signal, and the nozzle detection system can obtain the first detection result based on the first amplified signal, such as the abnormal nozzle group; after all the abnormal nozzle groups are obtained, each abnormal nozzle group is detected one by one, that is, the fourth electrical signal corresponding to the second electrical signal is amplified by the first integral amplifier circuit to obtain the second amplified signal, and then the second amplified signal is amplified by the second integral amplifier circuit to obtain the third amplified signal, and the nozzle detection system can obtain the second detection result based on the third amplified signal, such as the abnormal nozzle in the abnormal nozzle group. Until the detection of a nozzle is completed.

[0081] The second concept of the present invention is: since in the first concept, a row of nozzle holes or multiple nozzle holes (for example, 5 nozzle holes) in a column of nozzle holes in a nozzle head can be divided into a group for two rounds of detection, then a row of nozzle holes or a column of nozzle holes in multiple nozzles can be divided into a group, so that after two rounds of detection, multiple nozzle holes can be detected at the same time. The detection principle is the same.

[0082] The second concept is described in detail. A printing device often has multiple rows and columns of printing heads in an array, for example Figure 3 As shown, there are 3 rows and 4 columns with a total of 12 print heads, and each row of print heads includes 4 print heads. Each print head can include OK Column Total For example, a commonly used nozzle of a certain type may include 400 rows and 8 columns, totaling 3,200 nozzles. Each row of nozzles may include If a row or column of nozzles includes P nozzles, then a row or column of nozzles includes A spray hole. , are all positive integers greater than 2, is a positive integer greater than 1.

[0083] It is understandable that in each nozzle, the row spacing between nozzles is smaller than the column spacing ( Figure 4 and Figure 5Therefore, based on the idea of ​​combining group detection and one-by-one detection in the second inventive concept, the third inventive concept is to further divide the detection method into two types: the first detection method uses columns as detection units; the second detection method uses rows as detection units. The following is a detailed description of the two detection methods.

[0084] In the first test method, the row is used as the test unit, and a row of nozzles includes nozzles, assuming that The nozzles are divided into multiple groups, such as A group of nozzle holes, each group of nozzle holes includes a plurality of (e.g. Figure 4 5) nozzles.

[0085] If the column is used as the detection unit, for example Figure 4 As shown, firstly, the nozzle row to be detected is controlled to reach the illumination area along a first moving direction, wherein the first moving direction is perpendicular to the nozzle row direction and also perpendicular to the light of the center of the light source.

[0086] Next, for each column of nozzles, perform the following steps:

[0087] (1) The first round of nozzle inspection:

[0088] Control all the nozzles (e.g. Figure 4 The five nozzles in the nozzle assembly (the five nozzles in the nozzle assembly) continuously drip ink in a preset order. In this continuous ink dripping process, the photosensitive diode 21 collects the first light intensity information after the five nozzles drip ink in the illumination area formed by the light source, and converts the first light intensity information into a first electrical signal, converts the first electrical signal into a third electrical signal (the first electrical signal is an analog current signal, and the third electrical signal is an analog voltage signal), and sends the third electrical signal to the first integral amplifier circuit. The first integral amplifier circuit amplifies the third electrical signal and finally obtains a first amplified signal. The first amplified signal is an analog signal. The nozzle detection system can determine whether the current nozzle group has an abnormality according to the first amplified signal.

[0089] All the nozzles in the second group of nozzles are controlled to perform the test in step (1) until the last group of nozzles 31 completes the above test.

[0090] (2) Second round of nozzle inspection:

[0091] After the abnormal nozzle group in each column of nozzles is determined, for each abnormal nozzle group, each nozzle in each abnormal nozzle group is controlled to drop ink one by one. During the ink dropping process of each nozzle, the photosensitive diode 21 collects the second light intensity information of a nozzle after dropping ink in the illumination area formed by the light source, and converts the second light intensity information into a second electrical signal, converts the second electrical signal into a fourth electrical signal (the second electrical signal is an analog current signal, and the fourth electrical signal is an analog voltage signal), sends the fourth electrical signal to the first integral amplifier circuit, the first integral amplifier circuit performs a first amplification process on the fourth electrical signal to obtain a second amplified signal, sends the second amplified signal to the second integral amplifier circuit, the second integral amplifier circuit performs a second amplification process, and finally obtains a third amplified signal. The third amplified signal is a digital signal, and the nozzle detection system can determine the abnormal nozzles in the current nozzle group according to the third amplified signal.

[0092] It should be noted that the time interval between continuous ink dripping is less than or equal to a preset time length; for example, the time interval between two adjacent nozzles during the continuous ink dripping process may be 25uS.

[0093] The time interval between each ink drop is greater than the preset time length, because the ink ejection time is related to the signal response time. For example, the time interval between two adjacent nozzles in the process of each ink drop may be 5 mS.

[0094] Continuous ink dripping requires a smaller time interval, and accordingly, the processing of the electrical signal also needs to be accelerated. To achieve this speed-up function, it is mainly necessary to configure the circuit structure of the first integral amplifier circuit.

[0095] From the above steps, it can be seen that each column of nozzles undergoes two rounds of detection. In the first round of nozzle detection, groups are used as detection units. Each group of nozzles includes a preset number of nozzles (for example, 5). After the first round of nozzle detection, abnormal nozzle groups can be determined. In the second round of detection, single nozzles are used as detection units. After the second round of detection, abnormal nozzles can be determined.

[0096] In the second detection method, if the detection unit is line, a row of printheads may include The preset number of rows of nozzle holes are divided into multiple groups of nozzle holes, each group of nozzle holes includes a preset number of (e.g. Figure 5 2) nozzle holes.

[0097] For example, a preset number of rows of nozzle holes are divided into a plurality of groups of nozzle holes, each group of nozzle holes includes a preset number of nozzle holes (for example Figure 5 2) nozzle holes.

[0098] If the detection unit is line, first control the preset number of lines (for example Figure 5The row of nozzles to be detected (row 2 in the figure) moves along the second moving direction to the illumination area, wherein the second moving direction is parallel to the column direction of the nozzles and perpendicular to the light from the center of the light source.

[0099] Next, for every two rows of nozzles, perform the following steps:

[0100] 1) The first round of nozzle detection:

[0101] Control all nozzles in the first group of nozzles (for example Figure 5 In the process of simultaneously dripping ink, the photodiode 21 collects the third light intensity information of the two nozzles after dripping ink in the illumination area formed by the light source, and converts the third light intensity information into a fifth electrical signal, and sends it to the first integral amplifier circuit, the first integral amplifier circuit amplifies the fifth electrical signal, and finally obtains the fifth amplified signal, the fifth amplified signal is an analog signal, and the nozzle detection system can judge whether there is an abnormality in the current nozzle group according to the fifth amplified signal.

[0102] All the nozzles in the second group of nozzles are controlled to perform the test in step (1) until the last group of nozzles 31 completes the above test.

[0103] 2) Second round of nozzle detection:

[0104] After the abnormal nozzle group in every two rows of nozzles is determined, for each abnormal nozzle group, each nozzle in each abnormal nozzle group is controlled to drop ink one by one. During the ink dropping process of each nozzle, the photosensitive diode 21 collects the fourth light intensity information of a nozzle after dropping ink in the illumination area formed by the light source, and converts the fourth light intensity information into a sixth electrical signal, and sends it to the first integral amplifier circuit. The first integral amplifier circuit performs a first amplification process on the fourth electrical signal to obtain a sixth amplified signal, and then sends it to the second integral amplifier circuit. The second integral amplifier circuit performs a second amplification process to finally obtain a seventh amplified signal. The seventh amplified signal is a digital signal. The nozzle detection system can determine the abnormal nozzles in the current nozzle group according to the seventh amplified signal.

[0105] It can be seen from the above steps that two rounds of detection are performed with every two rows of nozzles as units. In the first round of nozzle detection, groups are used as detection units, and each group of nozzles includes a preset number (for example, 2) of nozzles (corresponding to the preset number of nozzle rows). After the first round of nozzle detection is completed, the abnormal nozzle group can be determined; in the second round of detection, a single nozzle is used as a detection unit. After the second round of detection is completed, the abnormal nozzle can be determined.

[0106] It should be noted that the above steps are described by taking two rows of nozzles as one detection unit because, in fact, the illumination range of an LED can generally only cover two rows of nozzles. If the light source includes two LEDs, four rows of nozzles can be used as one detection unit for detection.

[0107] In both detection methods, the first round of nozzle detection is to divide the nozzles into groups first, and then drip ink continuously or simultaneously for each nozzle group. The photosensitive diode collects light intensity information and forms an electrical signal, which is processed by the first integral amplifier circuit so that after the first round of nozzle detection, all abnormal nozzle groups can be determined. In the second round of detection, all nozzles in each abnormal group drip ink one by one, and the photosensitive diode collects light intensity information and forms an electrical signal. The first integral amplifier circuit and the second integral amplifier circuit process it in turn so that after the second round of detection, the abnormal nozzles in each nozzle group can be determined, thereby determining all abnormal nozzles. Whether it is the first detection method or the second detection method, there is no need to detect the nozzles one by one, which greatly reduces the detection time and improves the detection efficiency.

[0108] The fourth concept of the present invention is: using light-emitting diodes instead of laser devices, firstly, it can greatly reduce costs, and secondly, the illumination area formed by light-emitting diodes is larger than the illumination area formed by laser beams. If the nozzle is slightly offset, the impact on the excitation device is greater than the impact on the light-emitting diodes. Therefore, the use of light-emitting diodes can also improve detection efficiency.

[0109] The light detection circuit of the present invention is described in detail below.

[0110] like Figure 1 As shown, the photodetector further includes a VI conversion circuit 24 and a peak detection circuit 25;

[0111] The photodiode 21 is connected to the VI conversion circuit 24; the input end of the first integral amplifier circuit 22 is connected to the output end of the VI conversion circuit 24; the input end of the peak detection circuit 25 is connected to the output end of the first integral amplifier circuit 22;

[0112] The VI conversion circuit 24 is used to convert the first electrical signal into a third electrical signal; the VI conversion circuit is also used to convert the second electrical signal into a fourth electrical signal;

[0113] The peak detection circuit 25 is used to accumulate a preset number of first amplified signals to obtain a first electrical signal to be detected;

[0114] The nozzle hole detection system is used to determine the abnormal nozzle hole group based on the first electrical signal to be detected.

[0115] Optionally, the first integral amplifier circuit uses a TP2412 amplifier.

[0116] It should be noted that it is mentioned above that continuous ink dripping requires a smaller time interval. Accordingly, the processing of electrical signals also needs to be accelerated. In order to achieve this speed-up function, the present invention has made the following improvements to the first integral amplifier circuit: the first operational amplifier in the traditional first integral amplifier circuit uses an amplifier of the MCP6002 model. In order to achieve continuous ink dripping in the present invention, the present invention uses an amplifier of the TP2412 model as the first operational amplifier. In order to match the TP2412 amplifier, the first integral amplifier circuit in the present invention also adds a capacitor to play a phase compensation role to prevent self-oscillation. The gain-bandwidth product of MCP6002 is 1MHz, and that of TP2412 is 10MHz. In other words, the gain-bandwidth product of TP2412 is 10 times that of MCP6002. Under the same gain, TP2412 allows a higher frequency to pass through. The higher the frequency, the shorter the inkjet interval time is allowed, and the less time is consumed in detection.

[0117] The output signal of the first integral amplifier circuit is an analog signal, and the peak detection circuit accumulates multiple analog signal peaks. Specifically, in the continuous ink dripping process, when the first ink drop is dripped, a first voltage is generated, the first integral amplifier circuit amplifies it, and the peak detection circuit starts to record the first voltage. When the second ink drop is dripped, a second voltage is generated, the first integral amplifier circuit amplifies it, and the peak detection circuit adds the second voltage to the first voltage to accumulate a second accumulated voltage, and so on. For example, if the size of the obstruction of the abnormal nozzle will affect the intensity of light sensed by the photodetector, correspondingly, the larger the obstruction, the higher the output voltage of the peak detection circuit. For example, a 6pl ink droplet obstruction will cause the circuit to generate a 1V voltage change, and a 12pl ink droplet obstruction corresponds to a 2V voltage change. The peak detection circuit can record these accumulated voltage changes. According to the above principle, if there are 5 nozzles in a group of nozzles that drip ink continuously, if the peak detection circuit outputs a voltage change of 5V, it can be indicated that this group of nozzles is normal. If the output voltage change is 4V or other values ​​less than 5V, it can be indicated that there are abnormal nozzles in this group of nozzles. In the second round of detection, ink is dripped one by one to further determine which nozzle is the abnormal nozzle.

[0118] It is understandable that the peak detection circuit can be composed of multiple resistors, multiple capacitors, an amplifying transistor, a first operational amplifier and a second operational amplifier. The specific connection method can refer to the relevant technology and will not be repeated here.

[0119] like Figure 1 As shown, the photodetector further includes a first waveform shaping circuit 26; the input end of the first waveform shaping circuit 26 is connected to the output end of the second integral amplifier circuit 23;

[0120] The first waveform shaping circuit 26 is used to perform analog-to-digital conversion on the third amplified signal to obtain a second signal to be detected; the second signal to be detected is a digital signal;

[0121] The nozzle hole detection system is also used to determine the abnormal nozzle hole based on the second signal to be detected.

[0122] It is understandable that the second integral amplifier circuit 23 can be composed of a third operational amplifier, multiple resistors and multiple capacitors. The specific connection method can refer to the relevant technology and will not be repeated here.

[0123] Optionally, the first waveform shaping circuit 26 is composed of a fourth operational amplifier, multiple resistors and multiple capacitors. The specific connection method can refer to the relevant technology and will not be repeated here.

[0124] Optionally, the first waveform shaping circuit 26 is composed of a first comparator, multiple resistors and multiple capacitors. The specific connection method can refer to the relevant technology and will not be repeated here.

[0125] It is understandable that the photoelectric detector also includes a controller, and the output end of the first waveform shaping circuit is connected to the controller to send an output signal to the controller.

[0126] In an optional implementation, a light path detection circuit; the input end of the light path detection circuit is connected to the output end of the VI conversion circuit; the light path detection circuit is used to monitor the path condition of the photoelectric detector.

[0127] Specifically, Figure 1 As shown, the optical path detection circuit includes an amplifier circuit 27 and a second waveform shaping circuit 28;

[0128] The input end of the amplifier circuit 27 is the input end of the optical path detection circuit, and the output end of the amplifier circuit 27 is connected to the input end of the second waveform shaping circuit 28;

[0129] The amplifier circuit 27 is used to amplify the third electrical signal or the fourth electrical signal to obtain a fourth amplified signal;

[0130] The second waveform shaping circuit 28 is used to perform analog-to-digital conversion on the fourth amplified signal to obtain a third signal to be detected; the third signal to be detected is a digital signal;

[0131] The nozzle detection system is also used to confirm whether the photoelectric detector works normally based on the third signal to be detected.

[0132] It is understandable that the amplifier circuit 27 can be composed of a fifth operational amplifier, multiple resistors and multiple capacitors. The specific connection method can refer to the relevant technology and will not be repeated here.

[0133] Optionally, the second waveform shaping circuit 28 may be composed of a sixth operational amplifier, multiple resistors and multiple capacitors. The specific connection method may refer to the relevant technology and will not be described in detail here.

[0134] Optionally, the second waveform shaping circuit 28 may be composed of a second comparator, multiple resistors and multiple capacitors. The specific connection method may refer to the relevant technology and will not be described in detail here.

[0135] The detection principle of the optical path detection circuit is: the photodetector senses the light intensity. When the light source is damaged or the light beam of the light source does not irradiate the detector, the light intensity sensed by the photodiode is 0, and the circuit can be characterized as a high level, otherwise the circuit is characterized as a low level. Since the VI conversion circuit outputs an analog signal, the second waveform shaping circuit can convert the analog signal into a digital signal to facilitate result judgment.

[0136] The embodiment of the present invention further provides a nozzle detection method, which is applied to the nozzle detection system. The following introduces a nozzle detection method provided by the embodiment of the present invention, which corresponds to the above-mentioned nozzle detection system and includes the above-mentioned first detection method and second detection method for the nozzle.

[0137] The nozzle detection system includes a light source and a photoelectric detector; the light source includes at least one light emitting diode; the light source and the photoelectric detector are arranged opposite to each other; the photoelectric detector includes at least a photosensitive diode, a first integral amplifier circuit and a second integral amplifier circuit;

[0138] like Figure 6 As shown, the nozzle detection method may include:

[0139] Step 110: the nozzle detection system receives the first electrical signal in the first round of nozzle detection;

[0140] Step 120: Sending a third electrical signal corresponding to the first electrical signal to a first integral amplifier circuit;

[0141] Step 130: receiving a first amplified signal obtained after the first integral amplifier circuit amplifies the third electrical signal;

[0142] Step 140: receiving a second electrical signal in the second round of nozzle detection; wherein the first electrical signal and the second electrical signal are both acquired by a photodiode collecting light intensity information of at least one nozzle after ink is dripped in a light area formed by light emission of a light source, and the light intensity information is converted; the first electrical signal and the second electrical signal are both analog current signals, and the third electrical signal and the fourth electrical signal are both analog voltage signals;

[0143] Step 150: sending a fourth electrical signal corresponding to the second electrical signal to a first integral amplifier circuit; the first integral amplifier circuit is used to amplify the fourth electrical signal to obtain a second amplified signal;

[0144] Step 160: Sending the second amplified signal to a second integral amplifier circuit;

[0145] Step 170: receiving a third amplified signal obtained by amplifying the second amplified signal by the second integrating amplifier circuit;

[0146] Step 180: Obtain a nozzle detection result based on the first amplified signal and the third amplified signal.

[0147] Optionally, the nozzle hole detection result may be whether the nozzle hole is abnormal, for example, whether the nozzle hole is blocked.

[0148] Optionally, the nozzle detection result may also be a calculation result of the ink drop size and ink drop velocity.

[0149] In an optional implementation, step 180 may specifically include:

[0150] determining an abnormal nozzle group based on the first amplified signal;

[0151] After the abnormal nozzle group is obtained, the abnormal nozzle is determined based on the third amplified signal.

[0152] The abnormal nozzle group is determined based on the first amplified signal, specifically including: if the accumulated voltage value corresponding to the first amplified signal is less than a first preset value, determining the nozzle group corresponding to the first amplified signal as the abnormal nozzle group.

[0153] Determining the abnormal nozzle based on the third amplified signal specifically includes: if the voltage value corresponding to the third amplified signal is less than the second preset value, determining the nozzle corresponding to the third amplified signal as the abnormal nozzle.

[0154] Optionally, before the nozzle detection system receives the first electrical signal, the method further includes:

[0155] Control the light source to emit light;

[0156] Controlling each column of nozzles in the plurality of nozzles to move to the illumination area along a first moving direction in sequence;

[0157] Controlling all nozzles in each group of nozzles in each column of nozzles to perform a continuous ink drop step in the illuminated area in sequence; wherein each group of nozzles includes a preset number of nozzles; the photosensitive diode collects first light intensity information after the plurality of nozzles continuously drop ink in the illuminated area, and converts the first light intensity information into a first electrical signal;

[0158] Alternatively, before the nozzle detection system receives the second electrical signal, the method further includes:

[0159] After each column of nozzles completes the continuous ink dripping step, all nozzles in each abnormal nozzle group in each column of nozzles are controlled to drip ink one by one; wherein the photosensitive diode collects the second light intensity information of each nozzle after dripping ink in the illuminated area, and converts the second light intensity information into a second electrical signal.

[0160] Corresponding to the second detection method mentioned above, before the nozzle detection system receives the fifth electrical signal, the method further includes:

[0161] Control the light source to emit light;

[0162] A preset number of nozzle rows in the plurality of nozzles are sequentially controlled to move along the second moving direction to the illumination area; for example, the preset number is 2.

[0163] Controlling all nozzles in each group of nozzles in a preset number of nozzle rows to perform a simultaneous ink dripping step; wherein each group of nozzles includes a second preset number of nozzles; the photosensitive diode collects third light intensity information after the preset number of nozzles continuously drip ink in the illuminated area, and converts the third light intensity information into a fifth electrical signal; and the fifth amplified signal is obtained based on the third electrical signal;

[0164] Alternatively, before the nozzle detection system receives the fifth electrical signal, the method further includes:

[0165] After the second preset number of nozzle rows complete the simultaneous ink dripping step, the preset number of nozzles in each abnormal nozzle group are controlled to drip ink one by one; wherein the photosensitive diode collects the fourth light intensity information of each nozzle after dripping ink in the illuminated area, and converts the fourth light intensity information into a fifth electrical signal; the seventh amplified signal is obtained based on the fourth electrical signal.

[0166] In an optional embodiment, the nozzle detection system may include a light-emitting diode, a photosensitive diode, a digital-to-analog conversion module, an optical path detection module, an analog detection module, and a digital detection module. The photosensitive diode is connected to the digital-to-analog conversion module to convert the detected light signal into a current signal and send it to the digital-to-analog conversion module. The digital-to-analog conversion module is connected to the optical path detection module, the analog detection module, and the digital detection module, respectively. The principle of the nozzle detection system is to control the light-emitting diode and the photosensitive diode to shoot at each other. When an ink drop passes through the light column, the light column is blocked, thereby changing the light intensity. According to whether the light intensity detected by the photosensitive diode changes, it is judged whether there is an abnormality in the nozzle.

[0167] Furthermore, the digital-to-analog conversion module may include a VI conversion circuit, wherein the VI conversion circuit is respectively connected to the photodiode, the optical path detection module, the analog detection module and the digital detection module, and the VI conversion circuit is used to convert the current sent by the photodiode into a voltage and send it to the optical path detection module, the analog detection module and the digital detection module.

[0168] Further, the optical path detection module may include a first amplifier circuit and a first comparator. The first amplifier circuit is connected to the VI conversion circuit and the first comparator respectively. The first amplifier circuit is used to amplify the voltage amplitude sent by the VI conversion circuit to increase the detection accuracy of the voltage signal. The first comparator is used to compare the voltage signal sent by the amplifier circuit with a preset threshold. It is understandable that in this embodiment, the light-emitting diode and the photosensitive diode are controlled to be opposite to each other. When the photosensitive diode detects the light of the light-emitting diode, it indicates that the optical path is unobstructed. In this embodiment, the first comparator is used to determine whether the photosensitive diode detects the light of the light-emitting diode, and the voltage signal sent by the VI conversion circuit is compared with the preset threshold by the first comparator. When the voltage signal is greater than the preset threshold, it indicates that the optical path is unobstructed and the test environment is normal. It should be noted that the threshold of the first comparator can be set to a lower value, such as 0.1V, and it is not necessary to detect various characteristics of the ink droplets, and it is only necessary to determine whether the optical path is unobstructed. When the photodiode detects the light of the LED, it indicates that the light path is unobstructed, and the first comparator displays 1. When the photodiode detects the light of the LED, it indicates that the light path is blocked, and the first comparator displays 0. By judging the output level of the comparator, it can be determined whether the light path is unobstructed.

[0169] Furthermore, the analog detection module may include a second amplifier circuit, a peak detection circuit and an analog output circuit. The second amplifier circuit is connected to the VI conversion circuit and the peak detection circuit respectively, and the analog output circuit is connected to the peak detection circuit. The second amplifier circuit is used to amplify the voltage amplitude sent by the VI conversion circuit to increase the detection accuracy of the voltage signal. The peak detection circuit is used to collect a valid voltage signal according to the amplified voltage signal sent by the second amplifier circuit, and send the valid voltage signal to the analog output circuit. The analog output circuit is used to quantitatively output and display the valid voltage signal. Specifically, the ink droplets can be controlled to be ejected in sequence between the photosensitive diode and the light-emitting diode, and multiple continuously falling ink droplets form an obstruction on the plane perpendicular to the connection direction of the photosensitive diode and the light-emitting diode. The shielding area corresponding to the cross-section of the multiple continuously falling ink droplets on the plane is formed. Since the size of the shielding area will affect the light intensity detected by the photosensitive diode, and then affect the voltage change value output by the analog output circuit, it can be understood that the larger the shielding area, the greater the voltage change value. For example, when the control is to eject ink droplets in sequence and continuously, there are three small ink droplets that can simultaneously form an obstruction area between the photosensitive diode and the light-emitting diode, and the voltage change value corresponding to the corresponding light intensity change value is 2V. When a certain nozzle is abnormal and cannot eject ink droplets, when the nozzle participates in the broken hole detection, there are only two small ink droplets that can simultaneously form an obstruction area between the photosensitive diode and the light-emitting diode, and the voltage change value corresponding to the corresponding light intensity change value must be less than 2V. For another example: the voltage change value corresponding to the obstruction area that can be simultaneously formed between the photosensitive diode and the light-emitting diode when the control is to eject ink droplets in sequence and continuously can be determined according to the nozzle model and type, as well as the type and size of the ejected ink droplets. For another example: according to the voltage value output by the analog output circuit, the voltage value output between the photosensitive diode and the light-emitting diode and the voltage value when there is no obstruction, the difference between the two is calculated as the target voltage value change, and then according to the ratio of the voltage value output by the analog output circuit to the target voltage value change, it is determined whether there is an abnormal nozzle and the number and position of the abnormal nozzles.

[0170] Further, the digital detection module may include a third amplifier circuit, a second comparator and a digital output circuit. The third amplifier circuit is connected to the VI conversion circuit and the second comparator respectively, and the digital output circuit is connected to the second comparator. The third amplifier circuit is used to amplify the voltage amplitude sent by the VI conversion circuit to increase the detection accuracy of the voltage signal. The second comparator is used to make a qualitative judgment on the amplified voltage signal sent by the third amplifier circuit, and send the judgment result to the digital output circuit. The digital output circuit is used to output and display the qualitative judgment result. Specifically, the ink droplets can be controlled to be ejected one by one or continuously between the photosensitive diode and the light-emitting diode, and the ink droplets falling one by one or multiple continuously falling ink droplets form an obstruction on the plane perpendicular to the connection direction of the photosensitive diode and the light-emitting diode. The obstruction area corresponding to the cross section of one or more falling ink droplets on the plane is formed. Since the size of the obstruction area will affect the light intensity detected by the photosensitive diode, and then affect the voltage value output by the third amplifier circuit, it is understandable that the voltage value is smaller when the obstruction area is larger. Take the scenario of controlling the continuous ejection of ink droplets as an example: when the control is to eject ink droplets in sequence, there are three small ink droplets that can simultaneously form an occlusion area between the photosensitive diode and the light-emitting diode. At this time, the voltage value output by the digital output circuit is 8V. When a certain nozzle is abnormal and cannot eject ink droplets, when the nozzle participates in the broken hole detection, there are only two small ink droplets that can simultaneously form an occlusion area between the photosensitive diode and the light-emitting diode. At this time, the voltage value output by the digital output circuit must be greater than 8V, and the threshold of the second comparator can be set to 8V. Another example: according to the model and type of the nozzle, the speed of the ejection, and the type and size of the ejected ink droplets, the voltage value corresponding to the occlusion area that can be simultaneously formed between the photosensitive diode and the light-emitting diode when the ink droplets are ejected can be determined, and then the threshold of the second comparator can be set. Another example: the voltage value output by the third amplifier circuit is input into the second comparator. When the voltage value output by the third amplifier circuit is greater than or equal to the threshold value of the second comparator, the second comparator outputs a high level and sends the high level to the digital output circuit. After receiving the high level, the digital output circuit outputs and displays 1. When the voltage value output by the third amplifier circuit is less than the threshold value of the second comparator, the second comparator outputs a low level and sends the low level to the digital output circuit. After receiving the low level, the digital output circuit outputs and displays 0.

[0171] It should be noted that in this embodiment, an optical path detection module is set up, which can pre-judge whether the optical path is unobstructed before the broken hole detection is performed, avoid the misjudgment of the broken hole detection caused by environmental factors, and improve the accuracy of the broken hole detection. The detection part is divided into an analog detection module and a digital detection module. The analog detection method has higher accuracy and can output values ​​such as 1.2V, 1.3V, etc., and can obtain the number and position information of the broken holes more specifically. According to the ratio of the voltage value output by the analog output circuit and the change in the target voltage value, it can be determined whether there are abnormal nozzles and the number and position of abnormal nozzles; the digital detection method has stronger anti-interference ability, and because the FPGA in the board card processes digital signals more conveniently, the efficiency of digital detection will be higher. By changing the threshold of the second comparator, single-hole detection or multi-hole simultaneous detection can be achieved, and values ​​such as 1V, 2V, etc. can be output. It can be seen that when a higher accuracy scene is required, the analog detection method can be selected, and when a stronger anti-interference ability and higher efficiency scene are required, the digital detection method can be selected. The present application includes an analog detection module and a digital detection module. The two detection methods are more flexible and more applicable to different scenes. The analog detection method and the digital detection method in this application can both realize single one-by-one detection and multiple continuous detection of the nozzles on the nozzle. It can be understood that the analog continuous detection requires the relationship between the ink droplet characteristics and the voltage change value to be obtained in advance, and the digital continuous detection requires the pre-calculation and setting of the threshold of the second comparator, but it can achieve better detection efficiency during the detection process, which is particularly effective in the large-scale nozzle detection scene. The preprocessing operation before the analog single one-by-one detection and the digital single one-by-one detection is relatively simple, but during the detection process, the ink droplets fall one by one at a lower speed, which will lead to low detection efficiency. The scene of continuous detection in this embodiment refers to the presence of different nozzles in the same row or column on the plane perpendicular to the connection direction of the photosensitive diode and the light-emitting diode, and multiple ink droplets are ejected in sequence to fall continuously and form light obstruction at the same time. The scene of one-by-one detection refers to the presence of different nozzles in the same row or column on the plane perpendicular to the connection direction of the photosensitive diode and the light-emitting diode, and multiple ink droplets are ejected in sequence to fall one by one, and only one ink droplet forms light obstruction at each moment. In addition, ink droplets from different nozzles in different rows along the connection direction of the photosensitive diode and the light-emitting diode and in the same column on a plane perpendicular to the connection direction of the photosensitive diode and the light-emitting diode can be sprayed one by one or continuously, which can further improve the efficiency of broken hole detection.

[0172] In an optional implementation, the nozzle detection system uses PWM technology to control the light source to emit light; the nozzle detection system controls the duty cycle based on the ink drop color information.

[0173] From the above content, we can see that, firstly, using PWM technology to control the light source can reduce the power consumption of the circuit. Secondly, using different duty cycles for ink droplets of different colors can avoid unnecessary power consumption, thereby further reducing the power consumption of the circuit. According to the detection scene data, such as ink drop color, ink type, mechanical length of the detection path, etc., the duty cycle can be controlled to control the light-emitting power of the light-emitting diode, which can ensure the quality of broken hole detection while reducing power consumption as much as possible. In the scene of large-scale broken hole detection of nozzles, the energy consumption of the nozzle detection system can be reduced. Especially in some scenes where charging is not convenient enough, the time of broken hole detection can be extended, which reduces the labor cost and energy consumption of repeated charging in this scene, and improves the user experience.

[0174] In an optional embodiment, the analog detection circuit in the nozzle detection system can be used to calculate the ink drop volume and ink drop velocity of each nozzle based on the ink drop information. Specifically, a volume-voltage curve can be generated based on the voltage value output by the analog output circuit when there is no obstruction between the photosensitive diode and the light-emitting diode, and the voltage value output by the analog output circuit when different volumes of ink droplets are sprayed between the photosensitive diode and the light-emitting diode as an obstruction, thereby realizing the detection of the ink drop volume. The ink drop velocity can also be calculated based on the time of the voltage change value caused by the ink droplet injection and the mechanical height of the nozzle detection system. This method for detecting the ink drop volume and velocity can be used to obtain the size of the obstruction area corresponding to the ink drop before the broken hole detection, and can also be used in other scenarios where the ink drop volume and falling velocity need to be detected.

[0175] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0176] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the claims of the present invention and their equivalents.

Claims

1. A nozzle detection method, characterized in that: The nozzle detection method is applied to a nozzle detection system; the nozzle detection system comprises a light source and a photoelectric detector; the light source comprises at least one light emitting diode; the light source and the photoelectric detector are arranged opposite to each other; The photodetector at least comprises a photosensitive diode, a first integral amplifier circuit and a second integral amplifier circuit; The nozzle detection method comprises: The nozzle detection system controls all nozzles in each group of nozzles in each column of nozzles to perform a continuous ink drop step in the illuminated area in sequence; wherein each group of nozzles includes a plurality of nozzles; the photosensitive diode collects first light intensity information after the plurality of nozzles continuously drop ink in the illuminated area, and converts the first light intensity information into a first electrical signal; receiving the first electrical signal in the first round of nozzle detection; Sending a third electrical signal corresponding to the first electrical signal to the first integrating amplifier circuit; receiving a first amplified signal obtained after the first integral amplifier circuit amplifies the third electrical signal; determining an abnormal nozzle group based on the first amplified signal; After each column of nozzles completes the continuous ink dripping step, all nozzles in each abnormal nozzle group in each column of nozzles are controlled to drip ink one by one; wherein the photosensitive diode collects second light intensity information of each nozzle after dripping ink in the light area, and converts the second light intensity information into a second electrical signal; receiving the second electrical signal in the second round of nozzle detection; sending a fourth electrical signal corresponding to the second electrical signal to the first integral amplifier circuit; the first integral amplifier circuit is used to amplify the fourth electrical signal to obtain a second amplified signal; the first electrical signal and the second electrical signal are both analog current signals, and the third electrical signal and the fourth electrical signal are both analog voltage signals; sending the second amplified signal to the second integrating amplifier circuit; receiving a third amplified signal obtained after the second amplified signal is amplified by the second integral amplifier circuit; Based on the third amplified signal, an abnormal nozzle hole is determined.

2. The nozzle detection method according to claim 1, characterized in that: Before controlling all the nozzles in each group of nozzles in each column of nozzles to sequentially perform ink dropping in the illuminated area, the method further includes: Controlling the light source to emit light; Each column of nozzles in the plurality of nozzles is controlled in sequence to move along a first moving direction to the illumination area; the first moving direction is perpendicular to the column direction of the nozzles.

3. The nozzle detection method according to claim 1, characterized in that: The determining of the abnormal nozzle group based on the first amplified signal includes: if the accumulated voltage value corresponding to the first amplified signal is less than a first preset value, determining the nozzle group corresponding to the first amplified signal as the abnormal nozzle group; The determining the abnormal nozzle hole based on the third amplified signal includes: if the voltage value corresponding to the third amplified signal is less than a second preset value, determining the nozzle hole corresponding to the third amplified signal as the abnormal nozzle hole.

4. The nozzle detection method according to claim 1, characterized in that: The nozzle detection system uses PWM technology to control the light source to emit light; the nozzle detection system controls the duty cycle based on ink drop color information.

5. A nozzle detection system, characterized in that: include: A light source and a photodetector; the light source comprises at least one light emitting diode; the light source is arranged opposite to the photodetector; The photodetector at least comprises a photosensitive diode, a first integral amplifier circuit and a second integral amplifier circuit; The output end of the first integral amplifier circuit is connected to the input end of the second integral amplifier circuit; The photosensitive diode is used to collect light intensity information of at least one nozzle after ink is dropped in the illuminated area formed by the light source, and convert the light intensity information in the first round of nozzle detection into a first electrical signal, or convert the light intensity information in the second round of nozzle detection into a second electrical signal; The first integral amplifier circuit is used to amplify a third electrical signal corresponding to the first electrical signal to obtain a first amplified signal; the first integral amplifier circuit is also used to amplify a fourth electrical signal corresponding to the second electrical signal to obtain a second amplified signal; The first electrical signal and the second electrical signal are both analog current signals, and the third electrical signal and the fourth electrical signal are both analog voltage signals; The second integral amplifier circuit is used to amplify the second amplified signal to obtain a third amplified signal; The nozzle detection system obtains a nozzle detection result based on the first amplified signal and the third amplified signal.

6. The nozzle detection system according to claim 5, characterized in that: The photoelectric detector also includes a VI conversion circuit and a peak detection circuit; The photosensitive diode is connected to the VI conversion circuit; the input end of the first integral amplifier circuit is connected to the output end of the VI conversion circuit; the input end of the peak detection circuit is connected to the output end of the first integral amplifier circuit; The VI conversion circuit is used to convert the first electrical signal into the third electrical signal; the VI conversion circuit is also used to convert the second electrical signal into the fourth electrical signal; The peak detection circuit is used to accumulate a preset number of first amplified signals to obtain a first electrical signal to be detected; The nozzle detection system is used to determine an abnormal nozzle group based on the first electrical signal to be detected.

7. The nozzle detection system according to claim 5, characterized in that: The photodetector further comprises a first waveform shaping circuit; the input end of the first waveform shaping circuit is connected to the output end of the second integral amplifier circuit; The first waveform shaping circuit is used to perform analog-to-digital conversion on the third amplified signal to obtain a second signal to be detected; the second signal to be detected is a digital signal; The nozzle hole detection system is further used to determine an abnormal nozzle hole based on the second signal to be detected.

8. The nozzle detection system according to claim 6, characterized in that: The photoelectric detector further comprises a light path detection circuit; the input end of the light path detection circuit is connected to the output end of the VI conversion circuit; the light path detection circuit is used to monitor the path condition of the photoelectric detector.

9. The nozzle detection system according to claim 8, characterized in that: The optical path detection circuit includes an amplification circuit and a second waveform shaping circuit; The input end of the amplifier circuit is the input end of the optical path detection circuit, and the output end of the amplifier circuit is connected to the input end of the second waveform shaping circuit; The amplifier circuit is used to amplify the third electrical signal or the fourth electrical signal to obtain a fourth amplified signal; The second waveform shaping circuit is used to perform analog-to-digital conversion on the fourth amplified signal to obtain a third signal to be detected; the third signal to be detected is a digital signal; The nozzle detection system is also used to confirm whether the photoelectric detector works normally based on the third signal to be detected.

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