An inkjet printhead and method of installation contact detection

Abstract

The present application provides a kind of ink-jet print head and its installation contact detection method, print head includes ink cartridge, connecting soft board, printing chip and contact detection module, connecting soft board includes the first soft board part and the second soft board part connected, first soft board part is installed in the bottom surface of ink cartridge, second soft board part is installed in the side surface of ink cartridge and is equipped with multiple contact pads, printing chip is located in the bottom surface of ink cartridge and is connected with first soft board part, contact detection module is installed on the surface of second soft board part and is electrically connected with contact pad and printing chip by conductive circuit to be used for detecting the contact state of contact pad and external equipment terminal.The ink-jet print head of the present application integrates contact detection module in connecting soft board, so that contact detection function and printing function of printing chip itself are decoupled, and high-reliability installation state detection closer to physical contact interface can be realized.In addition, different models of ink-jet printing chip can only replace corresponding contact detection module, which helps to reduce the cost of wafer.

Description

Technical Field

[0001] This invention belongs to the field of inkjet printing technology and relates to an inkjet printhead and its installation contact detection method. Background Technology

[0002] With the increasing precision and frequency of inkjet printing, ensuring the stability of the printhead's electrical connection is crucial. Traditional solutions often integrate the detection circuitry within the printhead chip, achieving functional integration but occupying expensive chip space and increasing costs. Because the detection point is located at the end of the electrical link, the system struggles to determine whether a fault originates from poor external contact, a damaged flexible printed circuit board (FPC), or an internal chip logic failure, resulting in a significant diagnostic blind spot. Furthermore, long-distance signal transmission is prone to false alarms under high-temperature interference, and the fixed hardware logic lacks cross-product compatibility.

[0003] Therefore, how to develop a solution that separates the detection function from the chip, brings it closer to the contact interface, and balances accuracy and economy has become an important technical problem that needs to be solved by those skilled in the art.

[0004] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide an inkjet printhead and its installation contact detection method to solve the problems of obvious diagnostic blind spots, false alarms, and high costs in existing contact detection schemes.

[0006] To achieve the above and other related objectives, the present invention provides an inkjet printhead, comprising:

[0007] Ink cartridge, wherein the bottom surface of the ink cartridge is provided with an ink flow channel;

[0008] A connecting flexible circuit board includes a first flexible circuit board portion and a second flexible circuit board portion connected together. The first flexible circuit board portion is mounted on the bottom surface of the ink cartridge, and the second flexible circuit board portion is mounted on one side of the ink cartridge and is provided with a plurality of contact pads. Conductive lines electrically connected to the contact pads are distributed in the connecting flexible circuit board.

[0009] A printing chip is located on the bottom surface of the ink cartridge and is connected to the first flexible circuit board. The top surface of the printing chip is provided with an ink inlet channel that communicates with the ink outlet channel. The bottom surface of the printing chip is provided with multiple nozzles that communicate with the ink inlet channel. The printing chip is provided with a printing drive circuit, which is electrically connected to the contact pad through the conductive line.

[0010] A contact detection module is installed on the surface of the second flexible board and electrically connected to the contact pad and the printed chip through the conductive line. The contact detection module is used to detect the contact status between the contact pad and the external device terminal.

[0011] Optionally, the contact detection module uses a packaged chip.

[0012] Optionally, the contact detection module may be mounted on the surface of the second flexible circuit board via surface mounting.

[0013] Optionally, the contact detection module includes logic gate circuits.

[0014] Optionally, the logic gate circuit includes:

[0015] The first NAND gate has its first input terminal used to input the address selection signal of the heating resistor element, and its second input terminal used to input the clock signal.

[0016] An inverter, wherein the input terminal of the inverter is used to input a load signal that converts the address selection signal from serial data to parallel data via a shift register, and the output terminal of the inverter is used to output the inverted load signal;

[0017] The second NAND gate has its first input terminal used to input a heating duration control signal for driving the heating resistor element, and its second input terminal used to input the inverted loading signal.

[0018] The OR gate has its first input connected to the output of the first NAND gate, its second input connected to the output of the second NAND gate, and its output used to output a contact detection signal.

[0019] Optionally, the contact detection module includes discrete components.

[0020] Optionally, the discrete device includes at least one of a resistor, diode, transistor, and MOSFET.

[0021] Optionally, the discrete device includes a diode connected between a first pad and a second pad, independent of the driving of the heating resistor element.

[0022] Optionally, the discrete device includes a fixed resistor connected between a third contact pad and a fourth contact pad, which are independent of the driving of the heating resistor element.

[0023] Optionally, the nozzle is provided with a heating resistor element, and the printing drive circuit is electrically connected to the heating resistor element.

[0024] The present invention also provides a method for detecting the installation contact of an inkjet printhead, comprising the following steps:

[0025] Provide an inkjet printhead as described in any of the above solutions;

[0026] The contact detection module is used to detect the contact state between the contact pad and the external device terminal.

[0027] Optionally, the detection method includes at least one of passive signal contact detection and active drive signal readback detection.

[0028] Optionally, the passive signal contact detection includes:

[0029] A positive bias voltage is applied between a first pad and a second pad, which are independent of the driving of the heating resistor element, by an external device. A diode is connected between the first pad and the second pad.

[0030] The positive voltage drop between the first pad and the second pad is detected by an external device to determine the contact connection status between the first pad and the second pad and the external terminal, wherein:

[0031] If the measured voltage drop is within the preset diode forward voltage range, the contact condition is determined to be normal.

[0032] If the measured pressure drop exceeds the specified range, the contact condition is determined to be abnormal.

[0033] Optionally, the passive signal contact detection includes:

[0034] A constant current is applied between a third pad and a fourth pad, which are independent of the heating resistor element drive, by an external device. A fixed resistor is connected between the third pad and the fourth pad.

[0035] The contact connection status between the third and fourth pads and the external terminals is determined by detecting the resistance value or loop current between the third and fourth pads and the external terminals using external devices, wherein:

[0036] If the deviation between the actual resistance value and the preset resistance value is within the allowable range, or the deviation between the actual current value and the preset current value is within the allowable range, then the contact state is determined to be normal.

[0037] If the deviation exceeds the allowable range, the contact state is determined to be abnormal.

[0038] Optionally, the active readback detection of the drive signal includes:

[0039] The contact detection module is used to perform logic processing on the address selection signal, clock signal, load signal and heating duration control signal related to the driving of the heating resistor element. The contact detection module is configured to output a low level only when the clock signal, the address selection signal and the heating duration control signal are high level and the load signal is low level, and the output contact detection signal is high level in all other input states.

[0040] The external device sends a preset test sequence to the signal terminals corresponding to the address selection signal, the clock signal, the loading signal, and the heating duration control signal, and reads the feedback result of the output signal of the contact detection module to determine the contact status of the contact pad. If the output signal is low, the contact status is determined to be normal; if the output signal is high, the contact status is determined to be abnormal.

[0041] As described above, the inkjet printhead of the present invention includes an ink cartridge, a flexible printed circuit board (FPCB), a print chip, and a contact detection module. The ink cartridge has an ink outlet channel on its bottom surface. The FPCB includes a first FPCB portion and a second FPCB portion connected together. The first FPCB portion is mounted on the bottom surface of the ink cartridge, and the second FPCB portion is mounted on one side of the ink cartridge and has multiple contact pads. Conductive lines electrically connected to the contact pads are distributed in the FPCB. The print chip is located on the bottom surface of the ink cartridge and is connected to the first FPCB portion. The top surface of the print chip has an ink inlet channel communicating with the ink outlet channel. The bottom surface of the print chip has multiple nozzles communicating with the ink inlet channel. The print chip has a print drive circuit, which is electrically connected to the contact pads via conductive lines. The contact detection module is mounted on the surface of the second FPCB portion and electrically connected to the contact pads and the print chip via conductive lines. The contact detection module is used to detect the contact state between the contact pads and external device terminals. The inkjet printhead of this invention integrates the contact detection module onto the flexible connector board, decoupling the contact detection function from the printing function of the printhead chip itself. Since the detection circuit is located away from the high-temperature inkjet zone, the feedback loop can be shortened, achieving highly reliable installation status detection that is closer to the physical contact interface. Furthermore, for different models of inkjet printhead chips, only the inexpensive contact detection module on the flexible connector board needs to be replaced; there is no need to redesign and re-fabricate the printhead chip, thus helping to reduce fabrication costs. Attached Figure Description

[0042] Figure 1 The diagram shown is a structural schematic of an inkjet printhead according to an embodiment of the present invention.

[0043] Figure 2 The diagram shows the structure of the connecting flexible circuit board in the inkjet printhead of the present invention in the installed state.

[0044] Figure 3 The diagram shows the structure of the connecting flexible plate in the inkjet printhead of the present invention in a flattened state.

[0045] Figure 4 The diagram shown is a schematic representation of the internal circuitry of the contact detection module in the inkjet printhead of the present invention in one embodiment.

[0046] Explanation of reference numerals in the attached figures

[0047] 1 ink cartridge 2 Connecting flexible board 201 First Flexible Circuit Section 202 Second flexible circuit section 203 Contact pads 204 conductive circuit 3 Printed Chip 4 Contact detection module 401 First AND NOT gate 402 inverter 403 Second NAND gate 404 OR gate 405 diode 406 Fixed resistor Detailed Implementation

[0048] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0049] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, or components.

[0050] Features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0051] In the detailed description of embodiments of the present invention, for ease of explanation, the schematic diagrams illustrating the device structure may be partially enlarged without adhering to the general scale, and the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. Furthermore, in actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0052] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the drawings for devices in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it may be the only layer between the two layers, or there may be one or more layers in between.

[0053] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0054] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0055] This invention provides an inkjet printhead; please refer to [link / reference]. Figure 1 The image shows a schematic diagram of the structure of the inkjet printhead in one embodiment, including an ink cartridge 1, a connecting flexible circuit board 2, a printing chip 3, and a contact detection module 4.

[0056] Specifically, the ink cartridge 1 is used to store the liquid ink required for printing and to continuously and stably supply ink to the print head.

[0057] As an example, the ink cartridge 1 has an ink storage main cavity (not shown), and the bottom surface of the ink cartridge 1 has an ink outlet channel (not shown) that communicates with the ink storage main cavity.

[0058] Specifically, the connecting flexible circuit board 2 includes a first flexible circuit board portion 201 and a second flexible circuit board portion 202 connected to each other. The first flexible circuit board portion 201 is installed on the bottom surface of the ink cartridge 1, and the second flexible circuit board portion 202 is installed on one side of the ink cartridge 1 and is provided with a plurality of contact pads 203. The connecting flexible circuit board 2 is provided with conductive lines 204 that are electrically connected to the contact pads 203.

[0059] Specifically, the contact pad 203 serves as the interface for electrical connection between the printhead and the printer motherboard terminals. The number and layout of the contact pads can be adjusted as needed.

[0060] In some embodiments, the plurality of contact pads 203 include, but are not limited to, one or more of the following: drive control signal pads, power ground pads, contact detection dedicated pads, and signal feedback pads. The drive control signal pads are used to transmit clock, data, load, and ignition enable signals. The power ground pads are used to provide operating power and grounding circuits for the printed chip 3 and the contact detection module 4. The contact detection dedicated pads are used to detect the crimping contact state between the contact pads and the terminals of external devices through passive detection. The signal feedback pads are used to transmit the output signal of the contact detection module 4 back to the external device to realize the contact state determination of the contact pads.

[0061] In some embodiments, each contact pad is integrally connected to the conductive line 204 inside the flexible connection board 2.

[0062] Specifically, the printing chip 3 is located on the bottom surface of the ink cartridge 1 and is connected to the first flexible circuit board 201. The top surface of the printing chip 3 is provided with an ink inlet channel (not shown) that communicates with the ink outlet channel. The bottom surface of the printing chip 3 is provided with multiple nozzles (not shown) that communicate with the ink inlet channel. The printing chip 3 is provided with a printing drive circuit, which is electrically connected to the contact pad 203 through the conductive line 204.

[0063] As an example, the printing chip 3 is a thermal printing chip. Correspondingly, a heating resistor element is provided in the nozzle. The printing drive circuit is electrically connected to the heating resistor element. By instantaneously passing a large current to the heating resistor element, the heating resistor element heats up rapidly, thereby causing the ink on the surface of the heating resistor element to vaporize instantly and generate steam bubbles. The expansion and compression of the bubbles cause the ink droplets to be ejected from the nozzle. After the power is cut off, the bubbles condense and contract, and the negative pressure replenishes the nozzle with new ink, waiting for the next ignition.

[0064] In some embodiments, the surface of the printing chip 3 is provided with electrode pads that are electrically connected to the printing drive circuit, and the end of the conductive line 204 is provided with a lead pad. The electrode pads and the lead pads are electrically interconnected by wire bonding.

[0065] In other embodiments, the surface of the printing chip 3 is provided with electrode pads that are electrically connected to the printing drive circuit, and the end of the conductive line 204 is provided with lead pads. The electrode pads and the lead pads are aligned and made in contact with each other by conductive adhesive.

[0066] In some other embodiments, the surface of the printing chip 3 is provided with metal bumps that are electrically connected to the printing drive circuit. The side of the printing chip 3 with the metal bumps faces the conductive lines 204 of the connecting flexible board 2. The printing chip 3 and the connecting flexible board 2 are electrically connected by a flip-chip bump connection method through reflow soldering or thermoforming.

[0067] Specifically, the contact detection function has been removed from the printed chip 3.

[0068] Specifically, the contact detection module 4 is mounted on the surface of the second flexible board portion 202 and electrically connected to the contact pad 203 and the printed chip 3 through the conductive line 204, and is used to detect the contact status between the contact pad 203 and the external device terminal.

[0069] Specifically, the contact detection module 4 receives the electrical signal from the external device, performs logical operations, and returns the signal to the external device through specific contact pads.

[0070] It should be noted that since the contact detection module 4 is integrated into the second flexible circuit board 202, it is far from the high-temperature inkjet zone and closer to the contact interface. This avoids the problem of false alarms caused by high-temperature interference during long-distance signal transmission, thus improving the reliability and accuracy of installation status detection. Furthermore, the separation of the detection and printing functions means that for different models of inkjet printing chips, only inexpensive components such as logic gates, diodes, and resistors on the connecting flexible circuit board need to be replaced, without redesigning and fabricating the printing chip itself, thereby helping to reduce costs.

[0071] For example, please refer to Figure 2 and Figure 3 ,in, Figure 2 The diagram shows the structure of the connecting flexible board 2 in the installed state. Figure 3 The diagram shows the structure of the connecting flexible board 2 in a flattened state.

[0072] In some embodiments, the contact detection module 4 employs a packaged chip.

[0073] In some embodiments, the contact detection module 4 is mounted on the surface of the second flexible board portion 202 using a surface mount technology (SMT).

[0074] As an example, the surface of the second flexible board portion 202 is reserved with mounting pads corresponding to the pins of the contact detection module 4. The pins of the contact detection module 4 are aligned and placed on the surface of the mounting pads and fixedly connected by solder joints.

[0075] It should be noted that the area of ​​the second flexible board portion 202 is relatively large, so there is no need to increase the design area for the newly added contact detection module 4. Only the layout of the conductive line 204 needs to be adjusted to adapt to the electrical connection of the contact detection module 4.

[0076] For example, please refer to Figure 4 The diagram shows a schematic of the internal circuitry of the contact detection module 4 in one embodiment, wherein the contact detection module 4 includes a power supply voltage signal terminal (VDD) and a ground terminal (GND).

[0077] As an example, the contact detection module 4 includes a logic gate circuit, which includes a first NAND gate 401, an inverter 402, a second NAND gate 403, and an OR gate 404. The first input terminal of the first NAND gate 401 is used to input the address selection signal (DATA) of the heating resistor element, and the second input terminal of the first NAND gate 401 is used to input a clock signal (CLK) for adjusting the transmission of various signals or other operations. The input terminal of the inverter 402 is used to input a load signal (LOA) that converts the address selection signal (DATA) from serial data to parallel data via a shift register. The inverter 402 outputs the inverted load signal (LOADN); the first input of the second NAND gate 403 is used to input the heating duration control signal (FIRE) for driving the heating resistor element, and the second input of the second NAND gate 403 is used to input the inverted load signal (LOADN); the first input of the OR gate 404 is connected to the output of the first NAND gate 401, the second input of the OR gate 404 is connected to the output of the second NAND gate 403, and the output of the OR gate 404 is used to output the contact detection output signal (OUT).

[0078] Specifically, the contact detection module 4 performs the following processing on the signals related to the driving of the heating resistor element: Figure 4 The logic shown is such that OUT outputs 0 only when CLK, FIRE, and DATA signals are all 1 and LOADN is 0; otherwise, OUT outputs 1 and the OUT result is fed back to the external device via the pads.

[0079] As an example, the contact detection module 4 further includes discrete components, which include at least one of resistors, diodes, transistors, and MOSFETs, or other devices that demonstrate connectivity. Figure 4 In the illustrated embodiment, the discrete device includes a diode 405 and a fixed resistor 406. The diode 405 is connected between a first pad (PAD1) and a second pad (PAD2) that are independent of the driving of the heating resistor element. The contact between the pad and the external device terminal can be determined by detecting the voltage between the pads. The fixed resistor 406 is connected between a third contact pad (PAD3) and a fourth contact pad (PAD4) that are independent of the driving of the heating resistor element. The connection status between the contact pad in this area and the external device terminal can be determined by detecting the current or resistance signal between the pads.

[0080] The present invention also provides a method for detecting the installation contact of an inkjet printhead, comprising the following steps:

[0081] S1: Provide an inkjet printhead as described in any of the above solutions;

[0082] S2: Use the contact detection module to detect the contact state between the contact pad and the external device terminal.

[0083] As an example, the detection method includes at least one of passive signal contact detection and active drive signal readback detection.

[0084] As an example, the passive signal contact detection includes:

[0085] (1) A positive bias voltage is applied between a first pad and a second pad, which are independent of the heating resistor element drive, by an external device, and a diode is connected between the first pad and the second pad;

[0086] (2) The positive voltage drop between the first pad and the second pad is detected by an external device to determine the contact connection status between the first pad and the second pad and the external terminal, wherein:

[0087] If the measured voltage drop is within the preset diode forward voltage range, the contact condition is determined to be normal.

[0088] If the measured pressure drop exceeds the specified range, the contact condition is determined to be abnormal.

[0089] As an example, the passive signal contact detection includes:

[0090] (1) A constant current is applied between a third pad and a fourth pad, which are independent of the heating resistor element drive, by an external device, and a fixed resistor is connected between the third pad and the fourth pad;

[0091] (2) By detecting the resistance value or loop current between the third pad and the fourth pad using external equipment, the contact connection status between the third pad and the fourth pad and the external terminal is determined, wherein:

[0092] If the deviation between the actual resistance value and the preset resistance value is within the allowable range, or the deviation between the actual current value and the preset current value is within the allowable range, then the contact state is determined to be normal.

[0093] If the deviation exceeds the allowable range, the contact state is determined to be abnormal.

[0094] As an example, the active readback detection of the drive signal includes:

[0095] (1) The contact detection module is used to perform logic processing on the address selection signal, clock signal, load signal and heating duration control signal related to the driving of the heating resistor element. The contact detection module is configured to output a low level only when the clock signal, the address selection signal and the heating duration control signal are high level and the load signal is low level, and the output contact detection signal is high level in all other input states.

[0096] (2) The external device sends a preset test sequence to the signal terminals corresponding to the address selection signal, the clock signal, the loading signal and the heating duration control signal, and reads the feedback result of the output signal of the contact detection module to determine the contact state of the contact pad. If the output signal is low, the contact state is determined to be normal; if the output signal is high, the contact state is determined to be abnormal.

[0097] The contact detection method of the present invention is decoupled from the function of the printing chip itself, which can achieve highly reliable installation status detection that is closer to the physical contact interface.

[0098] In summary, the inkjet printhead of the present invention includes an ink cartridge, a flexible printed circuit board (FPCB), a print chip, and a contact detection module. The ink cartridge has an ink outlet channel on its bottom surface. The FPCB includes a first FPCB portion and a second FPCB portion connected together. The first FPCB portion is mounted on the bottom surface of the ink cartridge, and the second FPCB portion is mounted on one side of the ink cartridge and has multiple contact pads. Conductive lines electrically connected to the contact pads are distributed in the FPCB. The print chip is located on the bottom surface of the ink cartridge and is connected to the first FPCB portion. The top surface of the print chip has an ink inlet channel communicating with the ink outlet channel. The bottom surface of the print chip has multiple nozzles communicating with the ink inlet channel. The print chip has a print drive circuit, which is electrically connected to the contact pads via conductive lines. The contact detection module is mounted on the surface of the second FPCB portion and electrically connected to the contact pads and the print chip via conductive lines. The contact detection module is used to detect the contact state between the contact pads and external device terminals. The inkjet printhead of this invention integrates the contact detection module onto a flexible connector board, decoupling the contact detection function from the printing function of the printhead chip itself. Because the detection circuit is located away from the high-temperature area of ​​the inkjet printer, the feedback loop is shortened, enabling highly reliable installation status detection that is closer to the physical contact interface. Furthermore, for different models of inkjet printhead chips, only the inexpensive contact detection module on the flexible connector board needs to be replaced; there is no need to redesign and re-fabricate the printhead chip, thus reducing fabrication costs. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial applicability.

[0099] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An inkjet printhead, characterized in that, include: Ink cartridge, wherein the bottom surface of the ink cartridge is provided with an ink flow channel; A connecting flexible circuit board includes a first flexible circuit board portion and a second flexible circuit board portion connected together. The first flexible circuit board portion is mounted on the bottom surface of the ink cartridge, and the second flexible circuit board portion is mounted on one side of the ink cartridge and is provided with a plurality of contact pads. Conductive lines electrically connected to the contact pads are distributed in the connecting flexible circuit board. A printing chip is located on the bottom surface of the ink cartridge and is connected to the first flexible circuit board. The top surface of the printing chip is provided with an ink inlet channel that communicates with the ink outlet channel. The bottom surface of the printing chip is provided with multiple nozzles that communicate with the ink inlet channel. The printing chip is provided with a printing drive circuit, which is electrically connected to the contact pad through the conductive line. A contact detection module is installed on the surface of the second flexible board and electrically connected to the contact pad and the printed chip through the conductive line. The contact detection module is used to detect the contact status between the contact pad and the external device terminal.

2. The inkjet printhead according to claim 1, characterized in that: The contact detection module uses a packaged chip.

3. The inkjet printhead according to claim 1, characterized in that: The contact detection module is mounted on the surface of the second flexible circuit board in a manner including surface mounting.

4. The inkjet printhead according to claim 1, characterized in that: The contact detection module includes logic gate circuits.

5. The inkjet printhead according to claim 4, characterized in that, The logic gate circuit includes: The first NAND gate has its first input terminal used to input the address selection signal of the heating resistor element, and its second input terminal used to input the clock signal. An inverter, wherein the input terminal of the inverter is used to input a load signal that converts the address selection signal from serial data to parallel data via a shift register, and the output terminal of the inverter is used to output the inverted load signal; The second NAND gate has its first input terminal used to input a heating duration control signal for driving the heating resistor element, and its second input terminal used to input the inverted loading signal. The OR gate has its first input connected to the output of the first NAND gate, its second input connected to the output of the second NAND gate, and its output used to output a contact detection signal.

6. The inkjet printhead according to claim 1, characterized in that: The contact detection module includes discrete components.

7. The inkjet printhead according to claim 6, characterized in that: The discrete devices include at least one of resistors, diodes, transistors, and MOSFETs.

8. The inkjet printhead according to claim 6, characterized in that: The discrete device includes a diode connected between a first pad and a second pad, which are independent of the driving of the heating resistor element.

9. The inkjet printhead according to claim 6, characterized in that: The discrete device includes a fixed resistor connected between a third contact pad and a fourth contact pad, which are independent of the driving of the heating resistor element.

10. The inkjet printhead according to claim 1, characterized in that: The nozzle is equipped with a heating resistor element, and the printing drive circuit is electrically connected to the heating resistor element.

11. A method for detecting the installation contact of an inkjet printhead, characterized in that, Includes the following steps: Provide an inkjet printhead as described in any one of claims 1 to 10; The contact detection module is used to detect the contact state between the contact pad and the external device terminal.

12. The inkjet printhead mounting contact detection method according to claim 11, characterized in that: The detection method includes at least one of passive signal contact detection and active readback detection of drive signal.

13. The inkjet printhead mounting contact detection method according to claim 12, characterized in that, The passive signal contact detection includes: A positive bias voltage is applied between a first pad and a second pad, which are independent of the driving of the heating resistor element, by an external device. A diode is connected between the first pad and the second pad. The positive voltage drop between the first pad and the second pad is detected by an external device to determine the contact connection status between the first pad and the second pad and the external terminal, wherein: If the measured voltage drop is within the preset diode forward voltage range, the contact condition is determined to be normal. If the measured pressure drop exceeds the specified range, the contact condition is determined to be abnormal.

14. The inkjet printhead mounting contact detection method according to claim 12, characterized in that, The passive signal contact detection includes: A constant current is applied between a third pad and a fourth pad, which are independent of the heating resistor element drive, by an external device. A fixed resistor is connected between the third pad and the fourth pad. The contact connection status between the third and fourth pads and the external terminals is determined by detecting the resistance value or loop current between the third and fourth pads and the external terminals using external devices, wherein: If the deviation between the actual resistance value and the preset resistance value is within the allowable range, or the deviation between the actual current value and the preset current value is within the allowable range, then the contact state is determined to be normal. If the deviation exceeds the allowable range, the contact state is determined to be abnormal.

15. The inkjet printhead mounting contact detection method according to claim 12, characterized in that, The active readback detection of the drive signal includes: The contact detection module is used to perform logic processing on the address selection signal, clock signal, load signal and heating duration control signal related to the driving of the heating resistor element. The contact detection module is configured to output a low level only when the clock signal, the address selection signal and the heating duration control signal are high level and the load signal is low level, and the output contact detection signal is high level in all other input states. The external device sends a preset test sequence to the signal terminals corresponding to the address selection signal, the clock signal, the loading signal, and the heating duration control signal, and reads the feedback result of the output signal of the contact detection module to determine the contact status of the contact pad. If the output signal is low, the contact status is determined to be normal; if the output signal is high, the contact status is determined to be abnormal.

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