Open circuit detection circuit and open circuit detection chip

Abstract

The utility model provides an open circuit detection circuit and an open circuit detection chip. The open circuit detection circuit specifically comprises a first voltage detection module and a control module. Wherein the detection end of the first voltage detection module is used for being electrically connected with the power supply end of a first target module; the first input end of the control module is electrically connected with the output end of the first voltage detection module. The output end of the first voltage detection module outputs a first level signal corresponding to the voltage of the power supply end of the first target module; the control module is used for determining the working state of the first target module according to the first level signal. It can be understood that the first voltage detection module is directly and electrically connected with the first target module, so that when the first target module is open-circuited, the first voltage detection module can directly detect whether the first target module is open-circuited or not, and then accurate detection of the open-circuit fault part is achieved.

Description

Technical Field

[0001] This application relates to the field of image forming technology, and more specifically to an open-circuit detection circuit and an open-circuit detection chip. Background Technology

[0002] In image forming apparatuses, the high-voltage generation circuit module is a crucial power supply unit driving the core functional components. It provides high-precision DC voltage to the developing roller (DR), supply roller (SR), and doclosing blade (DB) modules via three connections. In practical use, the DR, SR, and DB modules work collaboratively to ensure the stability and accuracy of the printed image; therefore, the reliability of their circuit connections directly affects print quality and equipment lifespan. To determine the reliability of the circuit connections of the DR, SR, and DB modules, related technologies perform open-circuit testing on the DR, DB, and SR modules based on the total current of the high-voltage generation circuit module.

[0003] Specifically, a current sensor or voltage divider detection circuit is usually installed at the output end of the high-voltage module. When a branch (DR module, DB module or SR module) becomes open-circuited due to poor contact, broken line or damaged component, the total current value will exceed the preset threshold due to load changes, thereby triggering an open-circuit fault alarm.

[0004] However, the total current detection technology of the high voltage generation circuit module can only reflect the overall output abnormality of the high voltage module and cannot distinguish the specific faulty branch. Therefore, the detection accuracy of open circuit faulty components is low.

[0005] It should be noted that the information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0006] In view of this, this application provides an open circuit detection circuit and an open circuit detection chip to solve the problem that the total current detection technology of the high voltage generation circuit module in the prior art can only reflect the overall output abnormality of the high voltage module and cannot distinguish the specific fault branch, thus resulting in low accuracy of open circuit fault detection.

[0007] In a first aspect, embodiments of this application provide an open-circuit detection circuit applied to an image forming apparatus. The high-voltage generation circuit module in the image forming apparatus supplies power to the powder supply roller module, the developing roller module, and the powder exiting blade module, respectively. The circuit includes:

[0008] A first voltage detection module, wherein the detection end of the first voltage detection module is used to be electrically connected to the power supply end of the first target module, the first voltage detection module is used to detect the voltage of the power supply end of the first target module, and outputs a first level signal corresponding to the voltage of the power supply end of the first target module at the output end of the first voltage detection module;

[0009] A control module, wherein the first input terminal of the control module is electrically connected to the output terminal of the first voltage detection module, and the control module is used to determine the working state of the first target module based on the first level signal;

[0010] The first target module is any one of the powder supply roller module, the developing roller module, and the powder discharge knife module; the working state of the first target module includes abnormal state and normal state.

[0011] In one possible implementation, it further includes: a second voltage detection module and / or a third voltage detection module;

[0012] The detection terminal of the second voltage detection module is used to be electrically connected to the power supply terminal of the second target module. The second voltage detection module is used to detect the voltage of the power supply terminal of the second target module and output a second level signal corresponding to the voltage of the power supply terminal of the second target module at the output terminal of the second voltage detection module.

[0013] The detection terminal of the third voltage detection module is used to be electrically connected to the power supply terminal of the third target module. The third voltage detection module is used to detect the voltage of the power supply terminal of the third target module and outputs a third level signal corresponding to the voltage of the power supply terminal of the third target module at the output terminal of the third voltage detection module.

[0014] The second input terminal of the control module is electrically connected to the output terminal of the second voltage detection module. The control module is used to determine the working state of the second target module based on the second level signal.

[0015] Wherein, the second target module is any one of the powder supply roller module, the developing roller module, and the powder exiting blade module; the third target module is any one of the powder supply roller module, the developing roller module, and the powder exiting blade module; the first target module, the second target module, and the third target module are different modules.

[0016] In one possible implementation, the system further includes: a first filtering module, wherein the input terminal of the first filtering module is electrically connected to the output terminal of the first voltage detection module, and the output terminal of the first filtering module is electrically connected to the first input terminal of the control module. The first filtering module is used to filter out interference signals in the first level signal and send the filtered first level signal to the control module.

[0017] In one possible implementation, it also includes: a second filtering module and / or a third filtering module;

[0018] The input terminal of the second filtering module is electrically connected to the output terminal of the second voltage detection module, and the output terminal of the second filtering module is electrically connected to the second input terminal of the control module. The second filtering module is used to filter out interference signals in the second level signal and send the filtered second level signal to the control module.

[0019] The input terminal of the third filtering module is electrically connected to the output terminal of the third voltage detection module, and the output terminal of the third filtering module is electrically connected to the third input terminal of the control module. The third filtering module is used to filter out interference signals in the third level signal and send the filtered third level signal to the control module.

[0020] One possible implementation also includes:

[0021] The level correction module has its input terminal electrically connected to the output terminal of the first voltage detection module, and its output terminal electrically connected to the first input terminal of the control module. The level correction module is used to correct the first level signal according to a preset level and output the corrected first level signal at the output terminal of the level shaping module.

[0022] In one possible implementation, the first voltage detection module specifically includes:

[0023] A first resistor, the first end of which is electrically connected to the output terminal of the high voltage generation circuit module, and the second end of which is electrically connected to the power supply terminal of the first target module.

[0024] The first optocoupler has a first terminal electrically connected to the first terminal of the first resistor, a second terminal electrically connected to the second terminal of the first resistor, and a third terminal grounded.

[0025] The second resistor has its first end electrically connected to the fourth end of the first optocoupler, and its second end electrically connected to a voltage source.

[0026] The node between the second resistor and the first optocoupler is electrically connected to the first input terminal of the control module, and the node between the second resistor and the first optocoupler is the output terminal of the first voltage detection module.

[0027] In one possible implementation, the first voltage detection module specifically includes:

[0028] A first diode, wherein a first end of the first diode is electrically connected to the output terminal of the high voltage generation circuit module, and a second end of the first diode is electrically connected to the power supply terminal of the first target module;

[0029] The first optocoupler has a first terminal electrically connected to the first terminal of the first diode, a second terminal electrically connected to the second terminal of the first diode, and a third terminal grounded.

[0030] The second resistor has its first end electrically connected to the fourth end of the first optocoupler, and its second end electrically connected to a voltage source.

[0031] The node between the second resistor and the first optocoupler is electrically connected to the first input terminal of the control module, and the node between the second resistor and the first optocoupler is the output terminal of the first voltage detection module.

[0032] In one possible implementation, the first voltage detection module specifically includes:

[0033] The first optocoupler has a first end for electrical connection to the output end of the high voltage generation circuit module, a second end for electrical connection to the power supply end of the first target module, and a third end for grounding.

[0034] The second resistor has its first end electrically connected to the fourth end of the first optocoupler, and its second end electrically connected to a voltage source.

[0035] The node between the second resistor and the first optocoupler is electrically connected to the first input terminal of the control module, and the node between the second resistor and the first optocoupler is the output terminal of the first voltage detection module.

[0036] In one possible implementation, the first filtering module specifically includes:

[0037] The third resistor, the first end of which is electrically connected to the output terminal of the first voltage detection module;

[0038] A first capacitor, wherein a first terminal of the first capacitor is electrically connected to a second terminal of the third resistor, and the second terminal of the first capacitor is grounded;

[0039] The node between the third resistor and the first capacitor is electrically connected to the first input terminal of the control module, and the node between the third resistor and the first capacitor is the output terminal of the first filter module; the first end of the third resistor is the input terminal of the first filter module.

[0040] In one possible implementation, the level correction module specifically includes:

[0041] The transistor has its base electrically connected to the output terminal of the first voltage detection module, and its emitter is grounded.

[0042] A fourth resistor, the first end of which is electrically connected to the base of the transistor, and the second end of which is electrically connected to the emitter of the transistor;

[0043] The fifth resistor has its first end electrically connected to a voltage source and its second end electrically connected to the collector of the transistor.

[0044] The node between the fifth resistor and the transistor is electrically connected to the first input terminal of the control module. The node between the fifth resistor and the transistor is the output terminal of the level correction module, and the base of the transistor is the input terminal of the level correction module.

[0045] In one possible implementation, the second voltage detection module specifically includes:

[0046] The second diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the second target module.

[0047] The second optocoupler has a first terminal electrically connected to the first terminal of the second diode, a second terminal electrically connected to the second terminal of the second diode, and a third terminal grounded.

[0048] The sixth resistor has its first end electrically connected to the fourth end of the second optocoupler, and its second end electrically connected to a voltage source.

[0049] The node between the sixth resistor and the second optocoupler is electrically connected to the second input terminal of the control module, and the node between the sixth resistor and the second optocoupler is the output terminal of the first voltage detection module.

[0050] In one possible implementation, the third voltage detection module specifically includes:

[0051] The third diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the third target module.

[0052] The third optocoupler has its first terminal electrically connected to the first terminal of the third diode, its second terminal electrically connected to the second terminal of the third diode, and its third terminal grounded.

[0053] The seventh resistor has its first end electrically connected to the fourth end of the third optocoupler, and its second end electrically connected to a voltage source.

[0054] The node between the seventh resistor and the third optocoupler is electrically connected to the third input terminal of the control module, and the node between the seventh resistor and the third optocoupler is the output terminal of the first voltage detection module.

[0055] In one possible implementation, when the open-circuit detection circuit includes the second voltage detection module and the third voltage detection module, it specifically includes:

[0056] A first diode, wherein a first end of the first diode is electrically connected to the output terminal of the high voltage generation circuit module, and a second end of the first diode is electrically connected to the power supply terminal of the first target module;

[0057] The first optocoupler has a first terminal electrically connected to the first terminal of the first diode, a second terminal electrically connected to the second terminal of the first diode, and a third terminal grounded.

[0058] The eighth resistor is electrically connected to the first terminal of the first optocoupler and the second terminal of the eighth resistor is electrically connected to the first input terminal of the control module.

[0059] The second diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the second target module.

[0060] The second optocoupler has a first terminal electrically connected to the first terminal of the second diode, a second terminal electrically connected to the second terminal of the second diode, and a third terminal grounded.

[0061] The ninth resistor, the fourth terminal of the second optocoupler is electrically connected to the first terminal of the ninth resistor, and the second terminal of the ninth resistor is electrically connected to the first input terminal of the control module;

[0062] The third diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the third target module.

[0063] The third optocoupler has its first terminal electrically connected to the first terminal of the third diode, its second terminal electrically connected to the second terminal of the third diode, and its third terminal grounded.

[0064] The tenth resistor, the fourth terminal of the third optocoupler is electrically connected to the first terminal of the tenth resistor;

[0065] The eleventh resistor has its first end electrically connected to the power supply; its second end is electrically connected to the second end of the tenth resistor; and the node between the tenth and eleventh resistors is electrically connected to the first input terminal of the control module.

[0066] In one possible implementation, when the open-circuit detection circuit includes the second voltage detection module and the third voltage detection module, it specifically includes:

[0067] A first diode, wherein a first end of the first diode is electrically connected to the output terminal of the high voltage generation circuit module, and a second end of the first diode is electrically connected to the power supply terminal of the first target module;

[0068] The first optocoupler has a first terminal electrically connected to the first terminal of the first diode, a second terminal electrically connected to the second terminal of the first diode, and a third terminal grounded.

[0069] The second diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the second target module.

[0070] The second optocoupler has a first terminal electrically connected to the first terminal of the second diode, a second terminal electrically connected to the second terminal of the second diode, and a third terminal electrically connected to the fourth terminal of the first optocoupler.

[0071] The third diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the third target module.

[0072] The third optocoupler has its first end electrically connected to the first end of the third diode, its second end electrically connected to the second end of the third diode, its third end electrically connected to the fourth end of the first optocoupler, and its fourth end electrically connected to the first input end of the control module.

[0073] Secondly, embodiments of this application provide an open-circuit detection chip, comprising:

[0074] The open-circuit detection circuit described in any one of the first aspects.

[0075] In this embodiment, the open-circuit detection circuit specifically includes a first voltage detection module and a control module. The detection terminal of the first voltage detection module is electrically connected to the power supply terminal of the first target module; the first input terminal of the control module is electrically connected to the output terminal of the first voltage detection module. The output terminal of the first voltage detection module outputs a first level signal corresponding to the voltage at the power supply terminal of the first target module; the control module is used to determine the operating state of the first target module based on the first level signal. It can be understood that since the first voltage detection module is directly electrically connected to the first target module, when the first target module is open-circuited, the first voltage detection module can directly detect whether the first target module is open-circuited, thereby achieving accurate detection of open-circuit faulty components. Attached Figure Description

[0076] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0077] Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of this application.

[0078] Figure 2 This is a schematic diagram of an open-circuit detection circuit provided in an embodiment of this application.

[0079] Figure 3 This is a schematic diagram of the structure of a first voltage detection module provided in an embodiment of this application.

[0080] Figure 4 This is a schematic diagram of another first voltage detection module provided in an embodiment of this application.

[0081] Figure 5 This is a schematic diagram of another first voltage detection module provided in an embodiment of this application.

[0082] Figure 6This application provides a schematic diagram of the structure of a level correction module.

[0083] Figure 7 This application provides a circuit schematic diagram for multi-channel detection.

[0084] Figure 8 Another circuit schematic for multiplexing detection is provided for embodiments of this application.

[0085] Figure 9 Another circuit schematic for multiplexing detection is provided for embodiments of this application. Detailed Implementation

[0086] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0087] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0088] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0089] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0090] In the image forming apparatus, the toner supply roller module is used to electrically adsorb toner particles in the toner cartridge and precharge the toner using the voltage difference with the developing roller module, thereby improving the adsorption efficiency of the developing roller; the toner discharge blade module is used to electrically adsorb toner particles in the toner cartridge and precharge the toner using the voltage difference with the developing roller, thereby improving the adsorption efficiency of the developing roller; the developing roller module is responsible for controlling the adsorption and uniform distribution of toner on the surface of the photosensitive drum through a high-voltage electric field.

[0091] The high-voltage generation circuit module is a crucial power supply unit driving the core functional components. It provides high-precision DC voltage to the developing roller module, the toner supply roller module, and the toner dispensing blade module through three connections, enabling these three modules to work collaboratively to ensure the stability and accuracy of the printed image. For ease of understanding, a specific application scenario will be illustrated below.

[0092] See Figure 1 This is a schematic diagram illustrating an application scenario provided by an embodiment of this application. For example... Figure 1 As shown, this application scenario illustrates an image forming apparatus. The image forming apparatus includes a high-voltage generation circuit module, a powder supply roller module, a developing roller module, and a powder exit blade module. Figure 1 It can be seen that the high-voltage generation circuit module supplies power to the developing roller module, the powder supply roller module, and the powder discharge blade module respectively.

[0093] In the prior art, in order to determine the reliability of the circuit connection of the DR module, SR module and DB module, open circuit detection is usually performed on the DR module, DB module and SR module based on the total current of the high voltage generation circuit module.

[0094] Specifically, a current sensor or voltage divider detection circuit is usually installed at the output end of the high-voltage module. When a branch (DR module, DB module or SR module) becomes open-circuited due to poor contact, broken line or damaged component, the total current value will exceed the preset threshold due to load changes, thereby triggering an open-circuit fault alarm.

[0095] However, the total current detection technology of the high voltage generation circuit module can only reflect the overall output abnormality of the high voltage module and cannot distinguish the specific faulty branch. Therefore, the detection accuracy of open circuit faulty components is low.

[0096] Understandably, the core problem with existing technology lies in the fact that the DR, SR, and DB modules share a common total current detection mechanism in the high-voltage generation circuit module, resulting in insufficient open-circuit fault location capabilities. When an open circuit occurs in a branch, although abnormal changes in the total current can be detected, the lack of independent monitoring and logical analysis of the current in each branch makes it impossible to accurately identify whether the open-circuit fault occurs in a specific branch corresponding to the DR, DB, or SR module, nor can it quickly locate the fault point through detection data. This lack of detection accuracy significantly prolongs equipment fault diagnosis time, reduces maintenance efficiency, and may even lead to the incorrect replacement of non-faulty modules due to misjudgment, increasing maintenance costs. Therefore, there is an urgent need for a technical solution capable of independent open-circuit detection and accurate location for branches of the DR, SR, and DB modules.

[0097] To address the aforementioned issues, in this embodiment, the open-circuit detection circuit specifically includes a first voltage detection module and a control module. The detection terminal of the first voltage detection module is electrically connected to the power supply terminal of the first target module; the first input terminal of the control module is electrically connected to the output terminal of the first voltage detection module. The output terminal of the first voltage detection module outputs a first level signal corresponding to the voltage at the power supply terminal of the first target module; the control module is used to determine the operating state of the first target module based on the first level signal. It is understood that since the first voltage detection module is directly electrically connected to the first target module, when the first target module is open-circuited, the first voltage detection module can directly detect whether the first target module is open-circuited, thereby achieving accurate detection of open-circuit faulty components. Specifically, a detailed description is provided below in conjunction with the accompanying drawings and specific embodiments.

[0098] See Figure 2 This is a schematic diagram of an open-circuit detection circuit provided in an embodiment of this application. As shown in the figure, in Figure 1 Based on this, the figure shows a first voltage detection module 201 and a control module 202. The detection terminal of the first voltage detection module is electrically connected to the power supply terminal of the first target module; the first input terminal A1 of the control module is electrically connected to the first voltage detection module. Specifically, the first voltage detection module detects the voltage at the power supply terminal of the first target module and outputs a first level signal corresponding to the voltage at the power supply terminal of the first target module at its output terminal; then, the control module determines the operating state of the first target module based on the first level signal.

[0099] It is understood that the first target module can be any one of the DR module, SR module, and DB module; the working state of the first target module includes abnormal state and normal state.

[0100] In this embodiment, the open-circuit detection circuit specifically includes a first voltage detection module and a control module. The detection terminal of the first voltage detection module is electrically connected to the power supply terminal of the first target module; the first input terminal of the control module is electrically connected to the output terminal of the first voltage detection module. The output terminal of the first voltage detection module outputs a first level signal corresponding to the voltage at the power supply terminal of the first target module; the control module is used to determine the operating state of the first target module based on the first level signal. It can be understood that since the first voltage detection module is directly electrically connected to the first target module, when the first target module is open-circuited, the first voltage detection module can directly detect whether the first target module is open-circuited, thereby achieving accurate detection of open-circuit faulty components.

[0101] The first voltage detection module described above has various specific circuit connection methods, which will be described in detail below with reference to the accompanying drawings.

[0102] Type 1:

[0103] In one possible implementation, the first voltage detection module specifically includes a first resistor, a first optocoupler, and a second resistor. See [link to details]. Figure 3 This is a schematic diagram of the structure of a first voltage detection module provided in an embodiment of this application. Figure 3 As shown, in Figure 1 Based on this, the first voltage detection module specifically includes a first resistor R1, a first optocoupler U1, and a second resistor R2.

[0104] The specific circuit connections are as follows: the first terminal of the first resistor R1 is electrically connected to the output terminal of the high-voltage generation circuit module, and the second terminal of the first resistor R1 is electrically connected to the power supply terminal of the first target module; the first terminal of the first optocoupler U1 is electrically connected to the first terminal of the first resistor R1, the second terminal of the first optocoupler U1 is electrically connected to the second terminal of the first resistor R1, and the third terminal of the first optocoupler U1 is grounded; the first terminal of the second resistor R2 is electrically connected to the fourth terminal of the first optocoupler U1, and the second terminal of the second resistor R2 is electrically connected to the voltage source. The node between the second resistor R2 and the first optocoupler U1 is electrically connected to the first input terminal of the control module, and the node between the second resistor R2 and the first optocoupler U1 is the output terminal of the first voltage detection module.

[0105] In practical applications, the high-voltage generation circuit module can provide both AC power and DC power (forward and reverse DC power) to the DR, SR, and DB modules. It is understood that the first voltage detection module corresponding to this embodiment can detect both AC and DC power supply conditions.

[0106] Specifically, in the first scenario, the high-voltage generation circuit module supplies AC power to the first target module:

[0107] When the first target module is electrically connected normally, and the high-voltage generation circuit module supplies reverse current to the first target module, the reverse current flows from the first terminal of the first optocoupler to the second terminal, thereby making the third and fourth terminals of the first optocoupler conduct. When the third and fourth terminals of the first optocoupler are conducting, a low level is output at the output terminal of the first voltage detection module. When the first target module is electrically connected normally, and the high-voltage generation circuit module supplies forward current to the first target module, the forward current does not flow from the first terminal of the first optocoupler to the second terminal. At this time, the third and fourth terminals of the first optocoupler are disconnected, thereby outputting a high level at the output terminal of the first voltage detection module. It can be understood that the first voltage detection module detects the AC power supply status, and when the first target module is electrically connected normally, the first level signal is a square wave level with high and low variations, and the frequency corresponding to this square wave level is the same as the frequency of the AC power.

[0108] When the first target module is electrically open-circuited and the high-voltage generation circuit module supplies reverse current to the first target module, the reverse current will not flow from the first terminal of the first optocoupler to the second terminal. At this time, the third and fourth terminals of the first optocoupler are disconnected, resulting in a high-level output at the output terminal of the first voltage detection module. When the first target module is electrically open-circuited and the high-voltage generation circuit module supplies forward current to the first target module, the forward current will not flow from the first terminal of the first optocoupler to the second terminal. At this time, the third and fourth terminals of the first optocoupler are disconnected, resulting in a high-level output at the output terminal of the first voltage detection module. It can be understood that the first voltage detection module detects the AC power supply status, and when the first target module is electrically open-circuited, the first level signal is high.

[0109] Similarly, when the first target module has poor contact and the high voltage generation circuit module supplies AC current to the first target module, the first level signal is a level signal that changes from high to low. However, the frequency of the first level signal is usually not fixed, and the frequency of the first level signal is usually different from the frequency of AC current.

[0110] Specifically, in the second scenario, the high-voltage generation circuit module supplies DC power to the first target module:

[0111] When the first target module is electrically connected correctly and the high-voltage generation circuit module supplies DC current to the first target module, the current flows through the first and second terminals of the first optocoupler, thereby making the third and fourth terminals of the first optocoupler conduct. When the third and fourth terminals of the first optocoupler are conducting, a low-level signal is output at the output terminal of the first voltage detection module. It can be understood that the first voltage detection module detects the DC power supply status, and when the first target module is electrically connected correctly, the first level signal is a low-level signal.

[0112] When the first target module is electrically open-circuited and the high-voltage generation circuit module supplies DC current to the first target module, the current will not flow through the first and second terminals of the first optocoupler. At this time, the third and fourth terminals of the first optocoupler are disconnected, resulting in a high-level output at the output terminal of the first voltage detection module. It can be understood that the first voltage detection module detects the DC power supply status, and when the first target module is electrically open-circuited, the first level signal is a high-level signal.

[0113] Similarly, when the first target module has poor contact and the high voltage generation circuit module supplies DC current to the first target module, the current will flow irregularly through the first end and the second end of the first optocoupler. At this time, the third end and the fourth end of the first optocoupler will be irregularly disconnected and connected, which will then output a high-low level signal, i.e., the first level signal, at the output end of the first voltage detection module. The frequency of the first level signal is usually not fixed.

[0114] Specifically, the first resistor mentioned above should be selected with an appropriate resistance value. It is understood that when the first target module is electrically connected normally and the first optocoupler is in the off state, if the resistance value of the first resistor is too large, it may exceed the optocoupler's withstand voltage. When the first target module is electrically connected normally and the first optocoupler is in the on state, if the resistance value of the first resistor is too small, current may not flow through the first optocoupler, affecting open-circuit detection. Therefore, the first resistor should be selected with an appropriate resistance value.

[0115] It should be pointed out that, Figure 3 The diagram illustrates the connection method of the first optocoupler, which can detect negative DC current, i.e., current flowing from the first target module to the high-voltage generation circuit module. It is understood that, depending on actual needs, the first terminal of the first optocoupler can also be electrically connected to the second terminal of the first resistor, and vice versa, to detect the connection status of current flowing from the high-voltage generation circuit module to the first target module.

[0116] Type Two:

[0117] In one possible implementation, the first voltage detection module specifically includes a first optocoupler and a second resistor.

[0118] It is understandable that when the high-voltage generation circuit module outputs a constant negative voltage or a constant positive voltage, the light-emitting side of the first optocoupler can be directly connected in series between the high-voltage generation circuit and the first target module. Specifically, taking the high-voltage generation circuit module outputting a constant negative voltage as an example, see [link to relevant documentation]. Figure 4 This is a schematic diagram of another first voltage detection module provided in an embodiment of this application. Figure 4 As shown, in Figure 1 Based on this, the first voltage detection module specifically includes a first optocoupler U1 and a second resistor R2.

[0119] The specific circuit connections are as follows: the first terminal of the first optocoupler U1 is electrically connected to the output terminal of the high-voltage generation circuit module; the second terminal of the first optocoupler U1 is electrically connected to the power supply terminal of the first target module; the third terminal of the first optocoupler U1 is grounded; the first terminal of the second resistor R2 is electrically connected to the fourth terminal of the first optocoupler U1; and the second terminal of the second resistor R2 is electrically connected to the voltage source. The node between the second resistor R2 and the first optocoupler U1 is electrically connected to the first input terminal of the control module, and the node between the second resistor R2 and the first optocoupler U1 is the output terminal of the first voltage detection module.

[0120] It is understandable that when the first target module is electrically connected normally and the high voltage generation circuit module supplies DC current to the first target module, the light-emitting side of the optocoupler will be turned on, thereby making the third terminal of the first optocoupler and the fourth terminal of the first optocoupler connected, and outputting a low level at the output terminal of the first voltage detection module. That is, when the first target module is electrically connected normally, the first level signal is a low level signal.

[0121] When the first target module is electrically open, the high voltage generating circuit module will not supply DC current to the first target module, and the light-emitting side of the optocoupler will be disconnected, thereby causing the output terminal of the first voltage detection module to output a high level. That is, when the first target module is electrically open, the first level signal is a high level signal.

[0122] When the first target module has poor contact, the high voltage generation circuit module will irregularly supply DC current to the first target module, which in turn causes the light-emitting side of the optocoupler to emit light irregularly, thereby causing the output terminal of the first voltage detection module to output a high-low level signal, that is, the first level signal is a high-low level signal.

[0123] Of course, the constant positive voltage of the high voltage generation circuit module can also be detected by connecting the light-emitting side of the first optocoupler in reverse series.

[0124] Third type:

[0125] In one possible implementation, the first voltage detection module specifically includes a first diode, a first optocoupler, and a second resistor. See [link to relevant documentation] for details. Figure 5 This is a schematic diagram of another first voltage detection module provided in an embodiment of this application. Figure 5 As shown, in Figure 1 Based on this, the first voltage detection module specifically includes a first diode D1, a first optocoupler U1, and a second resistor R2.

[0126] The specific circuit connections are as follows: the first terminal of the first diode D1 is electrically connected to the output terminal of the high-voltage generation circuit module, and the second terminal of the first diode D1 is electrically connected to the power supply terminal of the first target module; the first terminal of the first optocoupler U1 is electrically connected to the first terminal of the first diode D1, the second terminal of the first optocoupler U1 is electrically connected to the second terminal of the first diode D1, and the third terminal of the first optocoupler U1 is grounded; the first terminal of the second resistor R2 is electrically connected to the fourth terminal of the first optocoupler U1, and the second terminal of the second resistor R2 is electrically connected to the voltage source. The node between the second resistor R2 and the first optocoupler U1 is electrically connected to the first input terminal of the control module, and the node between the second resistor R2 and the first optocoupler U1 is the output terminal of the first voltage detection module. It can be understood that the first voltage detection module corresponding to this embodiment can detect both AC and DC power supply conditions.

[0127] At this time, the electrical signal of the first level corresponding to different power supply scenarios (AC power supply and reverse DC power supply) is the same as the analysis of the first level signal output by the first type of first voltage detection module above. Specifically, when the first voltage detection module detects AC power supply and the first target module is electrically connected normally, the first level signal is a square wave with varying high and low levels, and the frequency of this square wave is the same as the frequency of AC power. When the first voltage detection module detects AC power supply and the first target module is electrically open, the first level signal is high. When the first target module has poor contact and the high-voltage generation circuit module supplies AC current to the first target module, the first level signal is a high and low level signal, and the frequency of this first level signal is usually different from the frequency of AC power. When the first voltage detection module detects DC power supply and the first target module is electrically connected normally, the first level signal is low. When the first voltage detection module detects DC power supply and the first target module is electrically open, the first level signal is high. When the first voltage detection module detects DC power supply and the first target module has poor contact, the first level signal is a high and low level signal, and the frequency of this first level signal is usually different from the frequency of AC power.

[0128] It should be noted that when the first target module has poor contact, the first level signal corresponding to the DC power supply and the AC power supply are not the same.

[0129] It should be pointed out that, Figure 5 The diagram illustrates the connection method of the first optocoupler, which can detect negative DC current, i.e., current flowing from the first target module to the high-voltage generation circuit module. It is understood that, depending on actual needs, the first terminal of the first optocoupler can also be electrically connected to the second terminal of the first diode, and vice versa, to detect the connection status of current flowing from the high-voltage generation circuit module to the first target module.

[0130] In practical applications, when following the above... Figure 5 When the first voltage detection module detects AC power, since the AC frequency of the developing voltage typically operates between 1 and 10 kHz, even with an open circuit at this frequency, the first optocoupler will still conduct (because the load is equivalent to resistive + capacitive, resulting in charging and discharging; the instantaneous current during charging and discharging is relatively large, leading to better conduction of the first optocoupler). Furthermore, the voltage level corresponds to the first level signal under normal power supply conditions. The higher the frequency of the AC power, the better the conduction performance of the first optocoupler.

[0131] To address the aforementioned issues, the circuitry of the first target module can be tested by reducing the AC frequency. It is understood that at lower AC frequencies, the detected first-level signals corresponding to the conduction and open-circuit states will show significant differences. To further ensure that the output first-level signal can be recognized by the control signal, a level correction module can be connected to the output of the first voltage detection module.

[0132] Specifically, in one possible implementation, the open-circuit detection circuit further includes a level correction module. Specifically, the input terminal of the level correction module is electrically connected to the output terminal of the first voltage detection module, and the output terminal of the level correction module is electrically connected to the first input terminal of the control module. The level correction module is used to correct the first level signal according to a preset level and output the corrected first level signal at its output terminal.

[0133] Furthermore, the level correction module can be designed based on the voltage shaping effect of transistors. For details, see [link to relevant documentation]. Figure 6 The diagram below illustrates the structure of a level correction module as provided in this embodiment. Figure 6 As shown, in Figure 5 Based on this, the level correction module specifically includes: transistor Q1, fourth resistor R4, and fifth resistor R5. Their electrical connections are as follows: the base of the transistor is electrically connected to the output terminal of the first voltage detection module; the emitter of the transistor is grounded; the first terminal of the fourth resistor is electrically connected to the base of the transistor; the second terminal of the fourth resistor is electrically connected to the emitter of the transistor; the first terminal of the fifth resistor is electrically connected to the voltage source; and the second terminal of the fifth resistor is electrically connected to the collector of the transistor.

[0134] It should be noted that the node between the fifth resistor and the transistor is electrically connected to the first input terminal of the control module, the node between the fifth resistor and the transistor is the output terminal of the level correction module, and the base of the transistor is the input terminal of the level correction module.

[0135] It is understandable that when the output level of the first voltage detection module changes from high to low, the transistor is cut off by setting the voltage divider on the base resistor of the transistor, and the first level signal is finally high. When the first target module is open, the optocoupler outputs a high level, the transistor is turned on, and the first level signal is finally low. After the signal output by the first optocoupler is shaped by the transistor, it can better distinguish between the on and off states.

[0136] In practical applications, due to the presence of many interference sources in the circuit, such as transformers, a first filter module can be connected in series between the first voltage detection module and the first module. Specifically, in one possible implementation, the open-circuit detection circuit further includes a first filter module. The input terminal of the first filter module is electrically connected to the output terminal of the first voltage detection module; the output terminal of the first filter module is electrically connected to the first input terminal of the control module; the first filter module is used to filter interference signals in the first level signal and send the filtered first level signal to the control module, thereby achieving accurate detection of open-circuit faulty components.

[0137] Furthermore, in one possible implementation, the first filtering module is an RC filter circuit. Specifically, the first filtering module includes a third resistor and a first capacitor. The first terminal of the third resistor is electrically connected to the output terminal of the first voltage detection module; the first terminal of the first capacitor is electrically connected to the second terminal of the third resistor, and the second terminal of the first capacitor is grounded.

[0138] It should be noted that the node between the third resistor and the first capacitor is electrically connected to the first input terminal of the control module, and the node between the third resistor and the first capacitor is the output terminal of the first filter module; the first end of the third resistor is the input terminal of the first filter module.

[0139] In practical applications, in order to accurately detect the circuit connection status of the DR module, SR module, and DB module, a voltage detection module can be connected to each of the DR module, SR module, and DB module.

[0140] Specifically, in one possible implementation, the path detection circuit further includes: a second voltage detection module and a third voltage detection module. The detection terminal of the second voltage detection module is electrically connected to the power supply terminal of the second target module. The second voltage detection module detects the voltage at the power supply terminal of the second target module and outputs a second-level signal corresponding to the voltage at the power supply terminal of the second target module at its output terminal. The detection terminal of the third voltage detection module is electrically connected to the power supply terminal of the third target module. The third voltage detection module detects the voltage at the power supply terminal of the third target module and outputs a third-level signal corresponding to the voltage at the power supply terminal of the third target module at its output terminal. The second input terminal of the control module is electrically connected to the output terminal of the second voltage detection module. The control module determines the operating state of the second target module based on the second-level signal.

[0141] It should be noted that the second target module is any one of the powder supply roller module, the developing roller module, and the powder exiting knife module; the third target module is any one of the powder supply roller module, the developing roller module, and the powder exiting knife module; and the first target module, the second target module, and the third target module are different modules.

[0142] Of course, since the high-voltage generation circuit module can detect whether there is an open circuit in the circuits corresponding to the powder supply roller module, the developing roller module, and the powder exiting knife module, the state of the third circuit can be deduced by detecting the state of any two of the two voltage detection circuits.

[0143] Specifically, in one possible implementation, the open-circuit detection circuit further includes a second voltage detection module or a third voltage detection module.

[0144] It is understandable that, since the second voltage detection module is directly electrically connected to the second target module and the third voltage detection module is directly electrically connected to the third target module, when the second target module or the third target module is open-circuited, the second voltage detection module or the third voltage detection module can directly detect whether the second target module or the third target module is open-circuited, thereby achieving accurate detection of open-circuit faulty components.

[0145] Furthermore, for ease of understanding, this application provides a circuit diagram in which a first voltage detection module, a second voltage detection module, and a third voltage detection module all participate in circuit detection. For details, see [link to specific documentation]. Figure 7 This application provides a circuit schematic diagram for multi-channel detection in its embodiments. For example... Figure 7 As shown, in Figure 5 Based on this, it also includes: a second diode D2, a second optocoupler U2, a sixth resistor R6, a third diode D3, a third optocoupler U3, and a seventh resistor R7.

[0146] Specifically, the circuit connections are as follows: the first terminal of the second diode is electrically connected to the output terminal of the high-voltage generation circuit module; the second terminal of the second diode is electrically connected to the power supply terminal of the second target module; the first terminal of the second optocoupler is electrically connected to the first terminal of the second diode; the second terminal of the second optocoupler is electrically connected to the second terminal of the second diode; the third terminal of the second optocoupler is grounded; the first terminal of the sixth resistor is electrically connected to the fourth terminal of the second optocoupler; the second terminal of the sixth resistor is electrically connected to the voltage source; the first terminal of the third diode is electrically connected to the output terminal of the high-voltage generation circuit module; the second terminal of the third diode is electrically connected to the power supply terminal of the third target module; the first terminal of the third optocoupler is electrically connected to the first terminal of the third diode; the second terminal of the third optocoupler is electrically connected to the second terminal of the third diode; the third terminal of the third optocoupler is grounded; the first terminal of the seventh resistor is electrically connected to the fourth terminal of the third optocoupler; the second terminal of the seventh resistor is electrically connected to the voltage source.

[0147] It should be noted that the node between the sixth resistor and the second optocoupler is electrically connected to the second input terminal of the control module, and the node between the sixth resistor and the second optocoupler is the output terminal of the first voltage detection module. The node between the seventh resistor and the third optocoupler is electrically connected to the third input terminal of the control module, and the node between the seventh resistor and the third optocoupler is the output terminal of the first voltage detection module.

[0148] Of course, as mentioned above, by combining the open-circuit detection function of the high-voltage generation circuit module, any two voltage detection modules can be selected from the first voltage detection module, the second voltage detection module, and the third voltage detection module to realize the detection of each module in the DR module, SR module, and DB module.

[0149] Of course, in one possible implementation, when the open-circuit detection circuit includes a second voltage detection module and / or a third voltage detection module, the open-circuit detection circuit correspondingly includes a second filter module and / or a third filter module. Specifically, the input terminal of the second filter module is electrically connected to the output terminal of the second voltage detection module; the output terminal of the second filter module is electrically connected to the second input terminal of the control module; the input terminal of the third filter module is electrically connected to the output terminal of the third voltage detection module, and the output terminal of the third filter module is electrically connected to the third input terminal of the control module.

[0150] Understandably, the second filtering module filters out interference signals in the second-level signal and sends the filtered second-level signal to the control module; the third filtering module filters out interference signals in the third-level signal and sends the filtered third-level signal to the control module. Ultimately, this allows the control module to more accurately detect the second and third target modules.

[0151] In one possible implementation, both the second and third filtering modules are RC filtering modules. Of course, the second and third filtering modules can also be other filtering circuits, and this application does not impose any specific restrictions on them.

[0152] In practical applications, the control module may not have three idle input terminals. To address this issue, the circuit structure of the first voltage detection module, the second voltage detection module, and the third voltage detection module can be adjusted so that the output terminal of a single control module can be used to detect each of the DR, SR, and DB modules.

[0153] In one possible implementation, when the open-circuit detection circuit contains three voltage detection modules simultaneously detecting the DR module, SR module, and DB module, it can be configured to indicate the disconnection of different modules by outputting different voltages. See [link to specific implementation details]. Figure 8 This provides another circuit schematic for multiplexing detection in the embodiments of this application. For example... Figure 8 As shown in the figure, the following components are shown: first diode D1, first optocoupler Q1, eighth resistor R8, second diode D2, second optocoupler Q2, ninth resistor R9, third diode D3, third optocoupler Q3, tenth resistor R10, and eleventh resistor R11.

[0154] The specific circuit connections are as follows: the first terminal of the first diode is electrically connected to the output terminal of the high-voltage generation circuit module; the second terminal of the first diode is electrically connected to the power supply terminal of the first target module; the first terminal of the first optocoupler is electrically connected to the first terminal of the first diode; the second terminal of the first optocoupler is electrically connected to the second terminal of the first diode; the third terminal of the first optocoupler is grounded; the fourth terminal of the first optocoupler is electrically connected to the first terminal of the eighth resistor; the second terminal of the eighth resistor is electrically connected to the first input terminal of the control module; the first terminal of the second diode is electrically connected to the output terminal of the high-voltage generation circuit module; the second terminal of the second diode is electrically connected to the power supply terminal of the second target module; the first terminal of the second optocoupler is electrically connected to the first terminal of the second diode; the second terminal of the second optocoupler is electrically connected to the second diode. The second end of the tube is electrically connected; the third end of the second optocoupler is grounded; the fourth end of the second optocoupler is electrically connected to the first end of the ninth resistor; the second end of the ninth resistor is electrically connected to the first input terminal of the control module; the first end of the third diode is electrically connected to the output terminal of the high voltage generation circuit module; the second end of the third diode is electrically connected to the power supply terminal of the third target module; the first end of the third optocoupler is electrically connected to the first end of the third diode; the second end of the third optocoupler is electrically connected to the second end of the third diode; the third end of the third optocoupler is grounded; the fourth end of the third optocoupler is electrically connected to the first end of the tenth resistor; the first end of the eleventh resistor is electrically connected to the power supply; the second end of the eleventh resistor is electrically connected to the second end of the tenth resistor; the node between the tenth and eleventh resistors is electrically connected to the first input terminal of the control module.

[0155] Understandably, taking DC power supply as an example, when the first target module, the second target module, and the third target module are all normally turned on, the voltage of the first level signal is:

[0156] (R8||R9||R10) / (R11+R8||R9||R10) VCC;

[0157] When both the second and third target modules are normally turned on, and the first target module is open-circuited, the voltage of the first level signal is:

[0158] (R9||R10) / (R11+R8||R9||R10) VCC;

[0159] When both the first and third target modules are normally turned on, and the second target module is open-circuited, the voltage of the first level signal is:

[0160] (R8||R10) / (R11+R8||R9||R10) VCC;

[0161] When both the second target module and the first target module are normally turned on, and the second target module is open-circuited, the voltage of the first level signal is:

[0162] (R8||R9) / (R11+R8||R9||R10) VCC.

[0163] Of course, in the DR module, SR module and DB module, any two or three modules may fail at the same time. Understandably, the corresponding output voltages will not be the same. For the sake of brevity, this application will not elaborate on this.

[0164] In practical applications, adjusting the connection method of the optocoupler circuit can also detect whether the DR module, SR module, and DB module are open circuits. Specifically, in one possible implementation, see [link to relevant documentation]. Figure 9 This provides another circuit schematic for multiplexing detection in the embodiments of this application. For example... Figure 9 As shown in the figure, the first diode D1, the first optocoupler U1, the second diode D2, the second optocoupler U2, the third diode D3, and the third optocoupler U3 are shown.

[0165] The specific circuit connections are as follows: the first terminal of the first diode is electrically connected to the output terminal of the high-voltage generation circuit module, and the second terminal of the first diode is electrically connected to the power supply terminal of the first target module; the first terminal of the optocoupler is electrically connected to the first terminal of the first diode, the second terminal of the first optocoupler is electrically connected to the second terminal of the first diode, and the third terminal of the first optocoupler is grounded; the first terminal of the second diode is electrically connected to the output terminal of the high-voltage generation circuit module, and the second terminal of the second diode is used to connect to the power supply terminal of the second target module; the first terminal of the second optocoupler is electrically connected to the first terminal of the second diode, the second terminal of the second optocoupler is electrically connected to the second terminal of the second diode, and the third terminal of the second optocoupler is electrically connected to the fourth terminal of the first optocoupler; the first terminal of the third diode is electrically connected to the output terminal of the high-voltage generation circuit module, and the second terminal of the third diode is electrically connected to the power supply terminal of the third target module; the first terminal of the third optocoupler is electrically connected to the first terminal of the third diode, the second terminal of the third optocoupler is electrically connected to the second terminal of the third diode, the third terminal of the third optocoupler is electrically connected to the fourth terminal of the first optocoupler, and the fourth terminal of the third optocoupler is electrically connected to the first input terminal of the control module.

[0166] Understandably, taking DC power supply as an example, when the first target module, the second target module, and the third target module are all normally turned on, the voltage of the first level signal is low; when any one of the first target module, the second target module, and the third target module is open, the voltage of the first level signal is high.

[0167] Corresponding to the above embodiments, this application also provides an open-circuit detection chip, which includes any of the open-circuit detection circuits described above. Specific functions are as described above; for the sake of brevity, this application will not repeat them.

[0168] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0169] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0170] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0171] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0172] The same or similar parts between the various embodiments in this specification can be referred to mutually. In particular, the device embodiments and terminal embodiments are basically similar to the method embodiments, so the description is relatively simple, and the relevant parts can be referred to the description in the method embodiments.

Claims

1. An open-circuit detection circuit, characterized in that, A high-voltage generation circuit module in an image forming apparatus is used to supply power to a powder supply roller module, a developing roller module, and a powder exit blade module, respectively. The circuit includes: A first voltage detection module, wherein the detection end of the first voltage detection module is used to be electrically connected to the power supply end of the first target module, the first voltage detection module is used to detect the voltage of the power supply end of the first target module, and outputs a first level signal corresponding to the voltage of the power supply end of the first target module at the output end of the first voltage detection module; A control module, wherein the first input terminal of the control module is electrically connected to the output terminal of the first voltage detection module, and the control module is used to determine the working state of the first target module based on the first level signal; The first target module is any one of the powder supply roller module, the developing roller module, and the powder discharge knife module; the working state of the first target module includes abnormal state and normal state.

2. The open-circuit detection circuit according to claim 1, characterized in that, Also includes: Second voltage detection module and / or third voltage detection module; The detection terminal of the second voltage detection module is used to be electrically connected to the power supply terminal of the second target module. The second voltage detection module is used to detect the voltage of the power supply terminal of the second target module and output a second level signal corresponding to the voltage of the power supply terminal of the second target module at the output terminal of the second voltage detection module. The detection terminal of the third voltage detection module is used to be electrically connected to the power supply terminal of the third target module. The third voltage detection module is used to detect the voltage of the power supply terminal of the third target module and outputs a third level signal corresponding to the voltage of the power supply terminal of the third target module at the output terminal of the third voltage detection module. The second input terminal of the control module is electrically connected to the output terminal of the second voltage detection module. The control module is used to determine the working state of the second target module based on the second level signal. Wherein, the second target module is any one of the powder supply roller module, the developing roller module, and the powder exiting blade module; the third target module is any one of the powder supply roller module, the developing roller module, and the powder exiting blade module; the first target module, the second target module, and the third target module are different modules.

3. The open-circuit detection circuit according to claim 1, characterized in that, Also includes: The first filtering module has its input terminal electrically connected to the output terminal of the first voltage detection module, and its output terminal electrically connected to the first input terminal of the control module. The first filtering module is used to filter out interference signals in the first level signal and send the filtered first level signal to the control module.

4. The open-circuit detection circuit according to claim 2, characterized in that, Also includes: Second filtering module and / or third filtering module; The input terminal of the second filtering module is electrically connected to the output terminal of the second voltage detection module, and the output terminal of the second filtering module is electrically connected to the second input terminal of the control module. The second filtering module is used to filter out interference signals in the second level signal and send the filtered second level signal to the control module. The input terminal of the third filtering module is electrically connected to the output terminal of the third voltage detection module, and the output terminal of the third filtering module is electrically connected to the third input terminal of the control module. The third filtering module is used to filter out interference signals in the third level signal and send the filtered third level signal to the control module.

5. The open-circuit detection circuit according to claim 1, characterized in that, Also includes: A level correction module is provided, wherein the input terminal of the level correction module is electrically connected to the output terminal of the first voltage detection module, and the output terminal of the level correction module is electrically connected to the first input terminal of the control module. The level correction module is used to correct the first level signal according to a preset level and output the corrected first level signal at the output terminal of the level correction module.

6. The open-circuit detection circuit according to claim 1, characterized in that, The first voltage detection module specifically includes: A first resistor, the first end of which is electrically connected to the output terminal of the high voltage generation circuit module, and the second end of which is electrically connected to the power supply terminal of the first target module. The first optocoupler has a first terminal electrically connected to the first terminal of the first resistor, a second terminal electrically connected to the second terminal of the first resistor, and a third terminal grounded. The second resistor has its first end electrically connected to the fourth end of the first optocoupler, and its second end electrically connected to a voltage source. The node between the second resistor and the first optocoupler is electrically connected to the first input terminal of the control module, and the node between the second resistor and the first optocoupler is the output terminal of the first voltage detection module.

7. The open-circuit detection circuit according to claim 1, characterized in that, The first voltage detection module specifically includes: A first diode, wherein a first end of the first diode is electrically connected to the output terminal of the high voltage generation circuit module, and a second end of the first diode is electrically connected to the power supply terminal of the first target module; The first optocoupler has a first terminal electrically connected to the first terminal of the first diode, a second terminal electrically connected to the second terminal of the first diode, and a third terminal grounded. The second resistor has its first end electrically connected to the fourth end of the first optocoupler, and its second end electrically connected to a voltage source. The node between the second resistor and the first optocoupler is electrically connected to the first input terminal of the control module, and the node between the second resistor and the first optocoupler is the output terminal of the first voltage detection module.

8. The open-circuit detection circuit according to claim 1, characterized in that, The first voltage detection module specifically includes: The first optocoupler has a first end for electrical connection to the output end of the high voltage generation circuit module, a second end for electrical connection to the power supply end of the first target module, and a third end for grounding. The second resistor has its first end electrically connected to the fourth end of the first optocoupler, and its second end electrically connected to a voltage source. The node between the second resistor and the first optocoupler is electrically connected to the first input terminal of the control module, and the node between the second resistor and the first optocoupler is the output terminal of the first voltage detection module.

9. The open-circuit detection circuit according to claim 3, characterized in that, The first filtering module specifically includes: The third resistor, the first end of which is electrically connected to the output terminal of the first voltage detection module; A first capacitor, wherein a first terminal of the first capacitor is electrically connected to a second terminal of the third resistor, and the second terminal of the first capacitor is grounded; The node between the third resistor and the first capacitor is electrically connected to the first input terminal of the control module, and the node between the third resistor and the first capacitor is the output terminal of the first filter module; the first end of the third resistor is the input terminal of the first filter module.

10. The open-circuit detection circuit according to claim 5, characterized in that, The level correction module specifically includes: The transistor has its base electrically connected to the output terminal of the first voltage detection module, and its emitter is grounded. A fourth resistor, the first end of which is electrically connected to the base of the transistor, and the second end of which is electrically connected to the emitter of the transistor; The fifth resistor has its first end electrically connected to a voltage source and its second end electrically connected to the collector of the transistor. The node between the fifth resistor and the transistor is electrically connected to the first input terminal of the control module. The node between the fifth resistor and the transistor is the output terminal of the level correction module, and the base of the transistor is the input terminal of the level correction module.

11. The open-circuit detection circuit according to claim 2, characterized in that, The second voltage detection module specifically includes: The second diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the second target module. The second optocoupler has a first terminal electrically connected to the first terminal of the second diode, a second terminal electrically connected to the second terminal of the second diode, and a third terminal grounded. The sixth resistor has its first end electrically connected to the fourth end of the second optocoupler, and its second end electrically connected to a voltage source. The node between the sixth resistor and the second optocoupler is electrically connected to the second input terminal of the control module, and the node between the sixth resistor and the second optocoupler is the output terminal of the first voltage detection module.

12. The open-circuit detection circuit according to claim 2, characterized in that, The third voltage detection module specifically includes: The third diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the third target module. The third optocoupler has its first terminal electrically connected to the first terminal of the third diode, its second terminal electrically connected to the second terminal of the third diode, and its third terminal grounded. The seventh resistor has its first end electrically connected to the fourth end of the third optocoupler, and its second end electrically connected to a voltage source. The node between the seventh resistor and the third optocoupler is electrically connected to the third input terminal of the control module, and the node between the seventh resistor and the third optocoupler is the output terminal of the first voltage detection module.

13. The open-circuit detection circuit according to claim 2, characterized in that, When the open-circuit detection circuit includes the second voltage detection module and the third voltage detection module, it specifically includes: A first diode, wherein a first end of the first diode is electrically connected to the output terminal of the high voltage generation circuit module, and a second end of the first diode is electrically connected to the power supply terminal of the first target module; The first optocoupler has a first terminal electrically connected to the first terminal of the first diode, a second terminal electrically connected to the second terminal of the first diode, and a third terminal grounded. The eighth resistor is electrically connected to the first terminal of the first optocoupler and the second terminal of the eighth resistor is electrically connected to the first input terminal of the control module. The second diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the second target module. The second optocoupler has a first terminal electrically connected to the first terminal of the second diode, a second terminal electrically connected to the second terminal of the second diode, and a third terminal grounded. The ninth resistor, the fourth terminal of the second optocoupler is electrically connected to the first terminal of the ninth resistor, and the second terminal of the ninth resistor is electrically connected to the first input terminal of the control module; The third diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the third target module. The third optocoupler has its first terminal electrically connected to the first terminal of the third diode, its second terminal electrically connected to the second terminal of the third diode, and its third terminal grounded. The tenth resistor, the fourth terminal of the third optocoupler is electrically connected to the first terminal of the tenth resistor; The eleventh resistor has its first end electrically connected to the power supply; its second end is electrically connected to the second end of the tenth resistor; and the node between the tenth and eleventh resistors is electrically connected to the first input terminal of the control module.

14. The open-circuit detection circuit according to claim 2, characterized in that, When the open-circuit detection circuit includes the second voltage detection module and the third voltage detection module, it specifically includes: A first diode, wherein a first end of the first diode is electrically connected to the output terminal of the high voltage generation circuit module, and a second end of the first diode is electrically connected to the power supply terminal of the first target module; The first optocoupler has a first terminal electrically connected to the first terminal of the first diode, a second terminal electrically connected to the second terminal of the first diode, and a third terminal grounded. The second diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the second target module. The second optocoupler has a first terminal electrically connected to the first terminal of the second diode, a second terminal electrically connected to the second terminal of the second diode, and a third terminal electrically connected to the fourth terminal of the first optocoupler. The third diode has a first end that is electrically connected to the output terminal of the high voltage generation circuit module, and a second end that is electrically connected to the power supply terminal of the third target module. The third optocoupler has its first end electrically connected to the first end of the third diode, its second end electrically connected to the second end of the third diode, its third end electrically connected to the fourth end of the first optocoupler, and its fourth end electrically connected to the first input end of the control module.

15. An open-circuit detection chip, characterized in that, include: The open-circuit detection circuit according to any one of claims 1 to 14.

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