Open circuit detection circuit and open circuit detection chip

Abstract

The invention 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 technologies, and more particularly to an open - circuit detection circuit and an open - circuit detection chip. Background Art

[0002] In an image forming apparatus, a high - voltage generation circuit module is an important power - supply unit for driving core functional components. It provides high - precision DC voltages to a developing roller (DR), a supply roller (SR), and a doctor blade (DB) module respectively through a three - point connection. In actual use, the DR module, the SR module, and the DB module work together to jointly ensure the stability and accuracy of printing and imaging. Therefore, the reliability of their circuit connections directly affects the printing quality and the device life. To determine the reliability of the circuit connections of the DR module, the SR module, and the DB module, in related technologies, open - circuit detection is performed on the DR module, the DB module, and the SR module based on the total current of the high - voltage generation circuit module.

[0003] Specifically, usually, a current sensor or a voltage - division detection circuit is set at the output end of the high - voltage module. When an open - circuit occurs in a certain branch (DR module, DB module, or SR module) due to poor contact, wire breakage, or component damage, the total current value will exceed a preset threshold due to the load change, 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 accuracy of open - circuit fault component detection is relatively low.

[0005] It should be noted that the information disclosed in the background art part of this application is only intended to deepen the understanding of the general background technology of this application, and should not be regarded as an admission or any form of implication that this information constitutes the prior art already known to those skilled in the art. Summary of the Invention

[0006] In view of this, this application provides an open - circuit detection circuit and an open - circuit detection chip, which are conducive to solving the problem in the prior art that 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, so the accuracy of open - circuit fault component detection is relatively low.

[0007] In a first aspect, an embodiment of this application provides an open - circuit detection circuit, which is applied to an image forming apparatus. The high - voltage generation circuit module in the image forming apparatus is used to supply power to a supply roller module, a developing roller module, and a doctor blade module respectively. The circuit includes: A first voltage detection module, wherein a detection end of the first voltage detection module is used for electrically connecting with a power supply end of a first target module, and the first voltage detection module is used for detecting a voltage of the power supply end of the first target module and outputting a first level signal corresponding to the voltage of the power supply end of the first target module at an output end of the first voltage detection module; A control module, wherein a first input end of the control module is electrically connected with the output end of the first voltage detection module, and the control module is used for determining an operating state of the first target module according to the first level signal; Wherein, the first target module is any one of the powder supply roller module, the developing roller module and the powder discharging blade module; the operating state of the first target module includes an abnormal state and a normal state.

[0008] In a possible implementation manner, it further includes: a second voltage detection module and / or a third voltage detection module; A detection end of the second voltage detection module is used for electrically connecting with a power supply end of a second target module, and the second voltage detection module is used for detecting a voltage of the power supply end of the second target module and outputting a second level signal corresponding to the voltage of the power supply end of the second target module at an output end of the second voltage detection module; A detection end of the third voltage detection module is used for electrically connecting with a power supply end of a third target module, and the third voltage detection module is used for detecting a voltage of the power supply end of the third target module and outputting a third level signal corresponding to the voltage of the power supply end of the third target module at an output end of the third voltage detection module; A second input end of the control module is electrically connected with the output end of the second voltage detection module, and the control module is used for determining an operating state of the second target module according to the second level signal; the second input end of the control module is electrically connected with the output end of the second voltage detection module, and the control module is used for determining an operating state of the second target module according to 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 discharging blade module; the third target module is any one of the powder supply roller module, the developing roller module and the powder discharging blade module; the first target module, the second target module and the third target module are different modules.

[0009] In a possible implementation, it further includes: a first filtering module, the input end of the first filtering module is electrically connected to the output end of the first voltage detection module, the output end of the first filtering module is electrically connected to the first input end of the control module, and 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.

[0010] In a possible implementation, it further includes: a second filtering module and / or a third filtering module; The input end of the second filtering module is electrically connected to the output end of the second voltage detection module, the output end of the second filtering module is electrically connected to the second input end of the control module, and 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 end of the third filtering module is electrically connected to the output end of the third voltage detection module, the output end of the third filtering module is electrically connected to the third input end of the control module, and 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.

[0011] In a possible implementation, it further includes: a level correction module, the input end of the level correction module is electrically connected to the output end of the first voltage detection module, the output end of the level shaping module is electrically connected to the first input end of the control module, and 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 end of the level shaping module.

[0012] In a possible implementation, the first voltage detection module specifically includes: a first resistor, the first end of the first resistor is used to be electrically connected to the output end of the high-voltage generation circuit module, and the second end of the first resistor is used to be electrically connected to the power supply end of the first target module; a first optocoupler, the first end of the first optocoupler is electrically connected to the first end of the first resistor, the second end of the first optocoupler is electrically connected to the second end of the first resistor, and the third end of the first optocoupler is grounded; a second resistor, the first end of the second resistor is electrically connected to the fourth end of the first optocoupler, and the second end of the second resistor is electrically connected to a voltage source; wherein, the node between the second resistor and the first optocoupler is electrically connected to the first input end of the control module, and the node between the second resistor and the first optocoupler is the output end of the first voltage detection module.

[0013] In a possible implementation, the first voltage detection module specifically includes: A first diode, the first end of the first diode is used to be electrically connected to the output end of the high-voltage generation circuit module, and the second end of the first diode is used to be electrically connected to the power supply end of the first target module; A first optocoupler, the first end of the first optocoupler is electrically connected to the first end of the first diode, the second end of the first optocoupler is electrically connected to the second end of the first diode, and the third end of the first optocoupler is grounded; A second resistor, the first end of the second resistor is electrically connected to the fourth end of the first optocoupler, and the second end of the second resistor is electrically connected to a voltage source; Wherein, the node between the second resistor and the first optocoupler is electrically connected to the first input end of the control module, and the node between the second resistor and the first optocoupler is the output end of the first voltage detection module.

[0014] In a possible implementation, the first voltage detection module specifically includes: A first optocoupler, the first end of the first optocoupler is used to be electrically connected to the output end of the high-voltage generation circuit module, the second end of the first optocoupler is used to be electrically connected to the power supply end of the first target module, and the third end of the first optocoupler is grounded; A second resistor, the first end of the second resistor is electrically connected to the fourth end of the first optocoupler, and the second end of the second resistor is electrically connected to a voltage source; Wherein, the node between the second resistor and the first optocoupler is electrically connected to the first input end of the control module, and the node between the second resistor and the first optocoupler is the output end of the first voltage detection module.

[0015] In a possible implementation, the first filtering module specifically includes: A third resistor, the first end of the third resistor is electrically connected to the output end of the first voltage detection module; A first capacitor, the first end of the first capacitor is electrically connected to the second end of the third resistor, and the second end of the first capacitor is grounded; Wherein, the node between the third resistor and the first capacitor is electrically connected to the first input end of the control module, and the node between the third resistor and the first capacitor is the output end of the first filtering module; the first end of the third resistor is the input end of the first filtering module.

[0016] In a possible implementation, the level correction module specifically includes: A triode, the base of the triode is electrically connected to the output end of the first voltage detection module, and the emitter of the triode is grounded; A fourth resistor, a first end of the fourth resistor is electrically connected to a base of the triode, and a second end of the fourth resistor is electrically connected to an emitter of the triode; A fifth resistor, a first end of the fifth resistor is electrically connected to a voltage source, and a second end of the fifth resistor is electrically connected to a collector of the triode; Wherein, a node between the fifth resistor and the triode is electrically connected to a first input end of the control module, the node between the fifth resistor and the triode is an output end of the level correction module, and the base of the triode is an input end of the level correction module.

[0017] In a possible implementation manner, the second voltage detection module specifically includes: A second diode, a first end of the second diode is used to be electrically connected to an output end of the high-voltage generation circuit module, and a second end of the second diode is used to be electrically connected to a power supply end of the second target module; A second optocoupler, a first end of the second optocoupler is electrically connected to the first end of the second diode, a second end of the second optocoupler is electrically connected to the second end of the second diode, and a third end of the second optocoupler is grounded; A sixth resistor, a first end of the sixth resistor is electrically connected to a fourth end of the second optocoupler, and a second end of the sixth resistor is electrically connected to a voltage source; Wherein, a node between the sixth resistor and the second optocoupler is electrically connected to a second input end of the control module, and the node between the sixth resistor and the second optocoupler is an output end of the first voltage detection module.

[0018] In a possible implementation manner, the third voltage detection module specifically includes: A third diode, a first end of the third diode is used to be electrically connected to an output end of the high-voltage generation circuit module, and a second end of the third diode is used to be electrically connected to a power supply end of the third target module; A third optocoupler, a first end of the third optocoupler is electrically connected to the first end of the third diode, a second end of the third optocoupler is electrically connected to the second end of the third diode, and a third end of the third optocoupler is grounded; A seventh resistor, a first end of the seventh resistor is electrically connected to a fourth end of the third optocoupler, and a second end of the seventh resistor is electrically connected to a voltage source; Wherein, a node between the seventh resistor and the third optocoupler is electrically connected to a third input end of the control module, and the node between the seventh resistor and the third optocoupler is an output end of the first voltage detection module.

[0019] In a possible implementation, when the switch detection circuit includes the second voltage detection module and the third voltage detection module, it specifically includes: A first diode, a first end of the first diode is used to be electrically connected to an output end of the high-voltage generation circuit module, and a second end of the first diode is used to be electrically connected to a power supply end of the first target module; A first optocoupler, a first end of the first optocoupler is electrically connected to the first end of the first diode, a second end of the first optocoupler is electrically connected to the second end of the first diode, and a third end of the first optocoupler is grounded; An eighth resistor, a fourth end of the first optocoupler is electrically connected to a first end of the eighth resistor, and a second end of the eighth resistor is electrically connected to a first input end of the control module; A second diode, a first end of the second diode is used to be electrically connected to the output end of the high-voltage generation circuit module, and a second end of the second diode is used to be electrically connected to a power supply end of the second target module; A second optocoupler, a first end of the second optocoupler is electrically connected to the first end of the second diode, a second end of the second optocoupler is electrically connected to the second end of the second diode, and a third end of the second optocoupler is grounded; A ninth resistor, a fourth end of the second optocoupler is electrically connected to a first end of the ninth resistor, and a second end of the ninth resistor is electrically connected to the first input end of the control module; A third diode, a first end of the third diode is used to be electrically connected to the output end of the high-voltage generation circuit module, and a second end of the third diode is used to be electrically connected to a power supply end of the third target module; A third optocoupler, a first end of the third optocoupler is electrically connected to the first end of the third diode, a second end of the third optocoupler is electrically connected to the second end of the third diode, and a third end of the third optocoupler is grounded; A tenth resistor, a fourth end of the third optocoupler is electrically connected to a first end of the tenth resistor; An eleventh resistor, a first end of the eleventh resistor is electrically connected to the power supply; a second end of the eleventh resistor is electrically connected to a second end of the tenth resistor, and a node between the tenth resistor and the eleventh resistor is electrically connected to the first input end of the control module.

[0020] In a possible implementation, when the switch detection circuit includes the second voltage detection module and the third voltage detection module, it specifically includes: A first diode, a first end of the first diode is used to be electrically connected to the output end of the high-voltage generation circuit module, and a second end of the first diode is used to be electrically connected to a power supply end of the first target module; The first optocoupler, the first end of the first optocoupler is electrically connected to the first end of the first diode, the second end of the first optocoupler is electrically connected to the second end of the first diode, and the third end of the first optocoupler is grounded; The second diode, the first end of the second diode is used to be electrically connected to the output end of the high-voltage generation circuit module, and the second end of the second diode is used to be electrically connected to the power supply end of the second target module; The second optocoupler, the first end of the second optocoupler is electrically connected to the first end of the second diode, the second end of the second optocoupler is electrically connected to the second end of the second diode, and the third end of the second optocoupler is electrically connected to the fourth end of the first optocoupler; The third diode, the first end of the third diode is used to be electrically connected to the output end of the high-voltage generation circuit module, and the second end of the third diode is used to be electrically connected to the power supply end of the third target module; The third optocoupler, 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 electrically connected to the fourth end of the first optocoupler, and the fourth end of the third optocoupler is electrically connected to the first input end of the control module.

[0021] In a second aspect, an open-circuit detection chip provided by an embodiment of the present application includes: The open-circuit detection circuit according to any one of the first aspect.

[0022] In the embodiment of the present application, the open-circuit detection circuit specifically includes a first voltage detection module and a control module. Among them, the detection end of the first voltage detection module is electrically connected to the power supply end of the first target module; the first input end of the control module is electrically connected to 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 to determine the working state of the first target module according to 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 realizing the precise detection of the open-circuit fault component. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0024] Figure 1A schematic diagram of an application scenario provided by an embodiment of the present application.

[0025] Figure 2 A schematic diagram of the structure of an open - circuit detection circuit provided by an embodiment of the present application.

[0026] Figure 3 A schematic diagram of the structure of a first voltage detection module provided by an embodiment of the present application.

[0027] Figure 4 A schematic diagram of the structure of another first voltage detection module provided by an embodiment of the present application.

[0028] Figure 5 A schematic diagram of the structure of another first voltage detection module provided by an embodiment of the present application.

[0029] Figure 6 A schematic diagram of the structure of a level correction module provided by an embodiment of the present application.

[0030] Figure 7 A circuit schematic diagram of multi - path detection provided by an embodiment of the present application.

[0031] Figure 8 A circuit schematic diagram of another multi - path detection provided by an embodiment of the present application.

[0032] Figure 9 A circuit schematic diagram of another multi - path detection provided by an embodiment of the present application. Detailed implementation manners

[0033] To better understand the technical solutions of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0034] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0036] It should be understood that the term "and / or" used herein is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this text generally represents an "or" relationship between the preceding and following associated objects.

[0037] In an image forming apparatus, a toner supply roller module over-connects to electrically adsorb toner particles in a toner cartridge, and uses the voltage difference from a developing roller module to pre-charge the toner, improving the adsorption efficiency of the developing roller; a blade module is used to electrically adsorb toner particles in the toner cartridge through connection, and uses the voltage difference from the developing roller to pre-charge the toner, 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 a photosensitive drum through a high-voltage electric field.

[0038] Among them, the high-voltage generation circuit module is an important power supply unit for driving core functional components. It provides high-precision DC voltage to the developing roller module, the toner supply roller module, and the blade module respectively through three-point connection, so that the developing roller module, the toner supply roller module, and the blade module work together to jointly ensure the stability and precision of printing and imaging. For ease of understanding, the following first gives an exemplary description of a specific application scenario.

[0039] See Figure 1 , which is a schematic diagram of an application scenario provided by an embodiment of the present application. As Figure 1 shown, an image forming apparatus is shown in this application scenario. Among them, the image forming apparatus includes a high-voltage generation circuit module, a toner supply roller module, a developing roller module, and a blade module. It can be known from Figure 1 that the high-voltage generation circuit module supplies power to the developing roller module, the toner supply roller module, and the blade module respectively.

[0040] In the prior art, in order to determine the reliability of the circuit connections of the DR module, the SR module, and the DB module, the open-circuit detection of the DR module, the DB module, and the SR module is usually based on the total current of the high-voltage generation circuit module.

[0041] Specifically, usually, a current sensor or a voltage division detection circuit is set at the output end of the high-voltage module. When a certain branch (DR module, DB module, or SR module) is open due to poor contact, line breakage, or component damage, the total current value will exceed a preset threshold due to the load change, thereby triggering an open-circuit fault alarm.

[0042] However, the total current detection technology of the high-voltage generation circuit module can only reflect the overall abnormal output of the high-voltage module and cannot distinguish the specific fault branch. Therefore, the accuracy of open-circuit fault component detection is relatively low.

[0043] It can be understood that the core problem of the prior art lies in that the DR module, the SR module, and the DB module share the total current detection mechanism of the high-voltage generation circuit module, resulting in insufficient open-circuit fault location ability. When an open circuit occurs in a certain branch, although the abnormal change of the total current can be detected, due to the lack of independent monitoring and logical analysis of the current in each branch, it is neither possible to accurately identify whether the open-circuit fault occurs in a specific branch corresponding to the DR module, the DB module, or the SR module, nor to quickly locate the fault point through the detection data. This problem of insufficient detection accuracy will significantly extend the equipment fault troubleshooting time, reduce the maintenance efficiency, and even may lead to the incorrect replacement of non-fault modules due to misjudgment, increasing the maintenance cost. Therefore, there is an urgent need for a technical solution that can independently detect and accurately locate open circuits in the branches of the DR module, the SR module, and the DB module.

[0044] In view of the above problems, in the embodiments of the present application, the open-circuit detection circuit specifically includes a first voltage detection module and a control module. Among them, 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 input end of the control module is electrically connected to 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 to determine the working state of the first target module according to 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 realizing the accurate detection of the open-circuit fault component. Specifically, it will be described in detail below in combination with the drawings and specific embodiments.

[0045] See Figure 2 , which is a schematic structural diagram of an open-circuit detection circuit provided by an embodiment of the present application. As shown in the figure, on the basis of Figure 1 , the figure shows a first voltage detection module 201 and a control module 202. Among them, the detection end of the first voltage detection module is electrically connected to the power supply end of the first target module; the first input end A1 of the control module is electrically connected to the first voltage detection module. Specifically, the first voltage detection module detects 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; then, the control module determines the working state of the first target module according to the first level signal.

[0046] It can be understood that the first target module is any one of the DR module, the SR module, and the DB module; the working state of the first target module includes an abnormal state and a normal state.

[0047] In the embodiment of the present application, the open-circuit detection circuit specifically includes a first voltage detection module and a control module. Among them, the detection end of the first voltage detection module is electrically connected to the power supply end of the first target module; the first input end of the control module is electrically connected to 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 to determine the working state of the first target module according to 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 realizing the precise detection of the open-circuit fault component.

[0048] There are various specific circuit connection methods for the first voltage detection module described above. Specifically, it will be described in detail below in conjunction with the drawings.

[0049] The first type: In a possible implementation manner, the first voltage detection module specifically includes a first resistor, a first optocoupler, and a second resistor. Specifically, refer to Figure 3 , which is a schematic structural diagram of a first voltage detection module provided by an embodiment of the present application. As Figure 3 shown, on the basis of Figure 1 , the first voltage detection module specifically includes a first resistor R1, a first optocoupler U1, and a second resistor R2.

[0050] The specific circuit connection relationship is: the first end of the first resistor R1 is electrically connected to the output end of the high-voltage generation circuit module, and the second end of the first resistor R1 is electrically connected to the power supply end of the first target module; the first end of the first optocoupler U1 is electrically connected to the first end of the first resistor R1, the second end of the first optocoupler U1 is electrically connected to the second end of the first resistor R1, and the third end of the first optocoupler U1 is grounded; the first end of the second resistor R2 is electrically connected to the fourth end of the first optocoupler U1, and the second end of the second resistor R2 is electrically connected to the voltage source. Among them, the node between the second resistor R2 and the first optocoupler U1 is electrically connected to the first input end of the control module, and the node between the second resistor R2 and the first optocoupler U1 is the output end of the first voltage detection module.

[0051] In practical applications, the high-voltage generation circuit module can supply alternating current to the DR module, the SR module, and the DB module, or can supply direct current (positive direct current and reverse direct current) to the DR module, the SR module, and the DB module. It can be understood that the first voltage detection module corresponding to the embodiment of the present application can detect both the alternating current power supply situation and the direct current power supply situation.

[0052] Specifically, in the first case, the high-voltage generation circuit module supplies alternating current to the first target module: When the first target module is electrically connected properly and the high-voltage generation circuit module delivers a reverse current to the first target module, the reverse current will flow from the first end of the first optocoupler to the second end of the first optocoupler, thereby causing the third end and the fourth end of the first optocoupler to conduct. When the third end and the fourth end of the first optocoupler conduct, a low level will be output at the output end of the first voltage detection module. When the first target module is electrically connected properly and the high-voltage generation circuit module delivers a forward current to the first target module, the forward current will not flow from the first end of the first optocoupler to the second end of the first optocoupler. At this time, the third end and the fourth end of the first optocoupler are disconnected, and thus a high level will be output at the output end of the first voltage detection module. It can be understood that when the first voltage detection module detects the AC power supply situation and the first target module is electrically connected properly, the first level signal is a square wave level that changes between high and low, and the frequency of this square wave level is the same as the frequency of the alternating current.

[0053] When the first target module has an open electrical connection and the high-voltage generation circuit module delivers a reverse current to the first target module, the reverse current will not flow from the first end of the first optocoupler to the second end of the first optocoupler. At this time, the third end and the fourth end of the first optocoupler are disconnected, and thus a high level will be output at the output end of the first voltage detection module. When the first target module has an open electrical connection and the high-voltage generation circuit module delivers a forward current to the first target module, the forward current will not flow from the first end of the first optocoupler to the second end of the first optocoupler. At this time, the third end and the fourth end of the first optocoupler are disconnected, and thus a high level will be output at the output end of the first voltage detection module. It can be understood that when the first voltage detection module detects the AC power supply situation and the first target module has an open electrical connection, the first level signal is a high level.

[0054] Similarly, when the first target module has poor contact and the high-voltage generation circuit module delivers an alternating current to the first target module, the first level signal is a level signal that changes between high and low, but the frequency of this first level signal is usually not fixed, and the frequency of this first level signal is usually different from the frequency of the alternating current.

[0055] Specifically, in the second case, the high-voltage generation circuit module provides direct current to the first target module: When the first target module is electrically connected properly and the high-voltage generation circuit module delivers a direct current to the first target module, the current will flow through the first end and the second end of the first optocoupler, thereby causing the third end and the fourth end of the first optocoupler to conduct. When the third end and the fourth end of the first optocoupler conduct, a low level will be output at the output end of the first voltage detection module. It can be understood that when the first voltage detection module detects the DC power supply situation and the first target module is electrically connected properly, the first level signal is a low level signal.

[0056] When the electrical connection of the first target module is open and the high-voltage generation circuit module delivers direct current to the first target module, the current will not flow through the first end and the second end of the first optocoupler. At this time, the third end of the first optocoupler is disconnected from the fourth end of the first optocoupler, and then a high level will be output at the output end of the first voltage detection module. It can be understood that when the first voltage detection module detects the DC power supply situation and the electrical connection of the first target module is open, the first level signal is a high-level signal.

[0057] Similarly, when the first target module has poor contact and the high-voltage generation circuit module delivers direct current to the first target module, the current will irregularly flow through the first end and the second end of the first optocoupler. At this time, the third end of the first optocoupler is irregularly disconnected and conducted with the fourth end of the first optocoupler, and then a level signal with high and low changes will be output at the output end of the first voltage detection module, that is, the first level signal, and the frequency of this first level signal is usually not fixed.

[0058] Among them, the first resistor described above should be selected with an appropriate resistance value. It can be understood that when the electrical connection of the first target module is normal and the first optocoupler is in the cut-off state, if the resistance value of the first resistor is too large, it may exceed the withstand voltage of the optocoupler. When the electrical connection of the first target module is normal and the first optocoupler is in the conducting state, if the resistance value of the first resistor is too small, it may cause the current not to flow through the first optocoupler, affecting the open-circuit detection. To sum up, the first resistor should be selected with an appropriate resistance value.

[0059] It should be noted that Figure 3 The connection method of the first optocoupler is shown, and it can detect negative-pressure direct current, that is, the current flows from the first target module to the high-voltage generation circuit module. It can be understood that according to actual needs, the first end of the first optocoupler can also be electrically connected to the second end of the first resistor, and the second end of the first optocoupler can be electrically connected to the first end of the first resistor to detect the connection situation of the current flowing from the high-voltage generation circuit module to the first target module.

[0060] The second type: In a possible implementation manner, the first voltage detection module specifically includes a first optocoupler and a second resistor.

[0061] It can be understood that when the high-voltage generation circuit module outputs a constant negative pressure or a constant positive pressure, 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 pressure as an example, see Figure 4 , which is another structural schematic diagram of the first voltage detection module provided by the embodiment of the present application. As Figure 4 shown, on the basis of Figure 1 , the first voltage detection module specifically includes a first optocoupler U1 and a second resistor R2.

[0062] The specific circuit connection relationship is as follows: The first end of the first optocoupler U1 is electrically connected to the output end of the high-voltage generation circuit module, and the second end of the first optocoupler U1 is electrically connected to the power supply end of the first target module; the third end of the first optocoupler U1 is grounded; the first end of the second resistor R2 is electrically connected to the fourth end of the first optocoupler U1, and the second end of the second resistor R2 is electrically connected to the voltage source. Among them, the node between the second resistor R2 and the first optocoupler U1 is electrically connected to the first input end of the control module, and the node between the second resistor R2 and the first optocoupler U1 is the output end of the first voltage detection module.

[0063] It can be understood that when the first target module is electrically connected normally and the high-voltage generation circuit module delivers direct current to the first target module, the light-emitting side of the optocoupler will conduct, thereby causing the third end and the fourth end of the first optocoupler to conduct, and a low level is output at the output end 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.

[0064] When the first target module is open-circuited and the high-voltage generation circuit module does not deliver direct current to the first target module, the light-emitting side of the optocoupler is disconnected, thereby causing a high level to be output at the output end of the first voltage detection module. That is, when the first target module is open-circuited, the first level signal is a high-level signal.

[0065] When the first target module has poor contact and the high-voltage generation circuit module delivers direct current to the first target module irregularly, the light-emitting side of the optocoupler emits light irregularly, thereby causing the output end of the first voltage detection module to output a level that changes between high and low. That is, the first level signal is a level signal that changes between high and low.

[0066] Of course, it is also possible to detect the constant positive voltage of the high-voltage generation circuit module by connecting the light-emitting side of the first optocoupler in reverse series.

[0067] The third type: In a possible implementation manner, the first voltage detection module specifically includes a first diode, a first optocoupler, and a second resistor. Specifically, refer to Figure 5 which is another structural schematic diagram of the first voltage detection module provided by the embodiments of the present application. As Figure 5 shown, on the basis of Figure 1 , the first voltage detection module specifically includes a first diode D1, a first optocoupler U1, and a second resistor R2.

[0068] The specific circuit connection relationship is as follows: The first end of the first diode D1 is electrically connected to the output end of the high-voltage generation circuit module, and the second end of the first diode D1 is used to be electrically connected to the power supply end of the first target module; The first end of the first optocoupler U1 is electrically connected to the first end of the first diode D1, the second end of the first optocoupler U1 is electrically connected to the second end of the first diode D1, and the third end of the first optocoupler U1 is grounded; The first end of the second resistor R2 is electrically connected to the fourth end of the first optocoupler U1, and the second end of the second resistor R2 is electrically connected to the voltage source. Among them, the node between the second resistor R2 and the first optocoupler U1 is electrically connected to the first input end of the control module, and the node between the second resistor R2 and the first optocoupler U1 is the output end of the first voltage detection module. It can be understood that the first voltage detection module corresponding to the embodiment of the present application can detect both AC power supply conditions and DC power supply conditions.

[0069] At this time, the analysis of the electrical signals of the first level corresponding to different power supply scenarios (AC power supply and reverse DC power supply) is the same as that of the first level signal output by the first type of first voltage detection module in the above text. That is, when the first voltage detection module detects the AC power supply condition and the first target module is electrically connected normally, the first level signal is a square wave level that changes between high and low, and the frequency corresponding to this square wave level is the same as the frequency of the alternating current; When the first voltage detection module detects the AC power supply condition and the first target module is electrically connected in an open circuit, the first level signal is a high level; When the first target module has poor contact and the high-voltage generation circuit module delivers an alternating current to the first target module, the first level signal is a level signal that changes between high and low, and the frequency of this first level signal is usually different from the frequency of the alternating current; When the first voltage detection module detects the DC power supply condition and the first target module is electrically connected normally, the first level signal is a low level signal; When the first voltage detection module detects the DC power supply condition and the first target module is electrically connected in an open circuit, the first level signal is a high level signal; When the first voltage detection module detects the DC power supply condition and the first target module has poor contact, the first level signal is a level signal that changes between high and low, and the frequency of this first level signal is usually different from the frequency of the alternating current.

[0070] It should be noted that when the first target module has poor contact, the first level signals corresponding to DC power supply and AC power supply are also different.

[0071] It should be noted that Figure 5 The connection method of the first optocoupler is shown, and it can detect the negative voltage direct current, that is, the current flows from the first target module to the high-voltage generation circuit module. It can be understood that according to actual needs, the first end of the first optocoupler can also be designed to be electrically connected to the second end of the first diode, and the second end of the first optocoupler is electrically connected to the first end of the first diode, for detecting the connection situation where the current flows from the high-voltage generation circuit module to the first target module.

[0072] In practical applications, when detecting AC power supply according to the first voltage detection module shown above Figure 5 in the text, since the AC frequency of the developing voltage generally works at 1 - 10KHZ, at this frequency, even if the backend is open, the first optocoupler will conduct (because the load is equivalent to resistive + capacitive, there will be charge and discharge, and the current will be relatively large during the charge and discharge instant. At this time, the conduction effect of the first optocoupler will be better), and the level is the same as the first level signal corresponding to the normal power supply situation. At the same time, the higher the frequency of the alternating current, the better the conduction effect of the first optocoupler.

[0073] To address the above problem, the circuit condition of the first target module can be tested by reducing the AC frequency. It can be understood that when the AC frequency is relatively low, there are obvious differences in the first level signals corresponding to the two states of conduction and open circuit detected. 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 end of the first voltage detection module.

[0074] Specifically, in a possible implementation manner, the open - circuit detection circuit further includes a level correction module. Specifically, the input end of the level correction module is electrically connected to the output end of the first voltage detection module, and the output end of the level correction module is electrically connected to the first input end 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 end of the level correction module.

[0075] Furthermore, the level correction module can be designed based on the voltage shaping effect of a triode. Specifically, referring to Figure 6 , a structural schematic diagram of a level correction module is provided for an embodiment of the present application. As Figure 6 shown, on the basis of Figure 5 , the level correction module specifically includes: triode Q1, fourth resistor R4, and fifth resistor R5. The electrical connection relationship is as follows: the base of the triode is electrically connected to the output end of the first voltage detection module; the emitter of the triode is grounded; the first end of the fourth resistor is electrically connected to the base of the triode; the second end of the fourth resistor is electrically connected to the emitter of the triode; the first end of the fifth resistor is electrically connected to the voltage source; the second end of the fifth resistor is electrically connected to the collector of the triode.

[0076] It should be noted that the node between the fifth resistor and the triode is electrically connected to the first input end of the control module. The node between the fifth resistor and the triode is the output end of the level correction module, and the base of the triode is the input end of the level correction module.

[0077] It can be understood that when the output level of the first voltage detection module changes from high to low, by setting the voltage division of the base resistor of the triode, the triode is cut off, and at this time the first level signal is finally high level; when the first target module is open-circuited, the optocoupler outputs a high level, then the triode conducts, and the first level signal is finally low level. The signal output by the first optocoupler can better distinguish the conduction and open-circuit states after being shaped by the triode.

[0078] In practical applications, since there are many interference sources in the circuit, such as transformers, etc., a first filtering module can be connected in series between the first voltage detection module and the first module. Specifically, in a possible implementation manner, the open-circuit detection circuit further includes a first filtering module. Among them, the input end of the first filtering module is electrically connected to the output end of the first voltage detection module; the output end of the first filtering module is electrically connected to the first input end of the control module; the first filtering module is used to filter the interference signals in the first level signal and send the filtered first level signal to the control module, thereby realizing the precise detection of the open-circuit faulty component.

[0079] Furthermore, in a possible implementation manner, the first filtering module is an RC filtering circuit. Specifically, the first filtering module includes a third resistor and a first capacitor. Among them, the first end of the third resistor is electrically connected to the output end of the first voltage detection module; the first end of the first capacitor is electrically connected to the second end of the third resistor, and the second end of the first capacitor is grounded.

[0080] It should be noted that the node between the third resistor and the first capacitor is electrically connected to the first input end of the control module, and the node between the third resistor and the first capacitor is the output end of the first filtering module; the first end of the third resistor is the input end of the first filtering module.

[0081] In practical applications, in order to accurately detect the circuit connection conditions 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.

[0082] Specifically, in a possible implementation, the path detection circuit further includes: a second voltage detection module and a third voltage detection module. Among them, the detection end of the second voltage detection module is electrically connected to the power supply end of the second target module. The second voltage detection module is configured to detect the voltage of the power supply end of the second target module and output a second level signal corresponding to the voltage of the power supply end of the second target module at the output end of the second voltage detection module; the detection end of the third voltage detection module is electrically connected to the power supply end of the third target module. The third voltage detection module is configured to detect the voltage of the power supply end of the third target module and output a third level signal corresponding to the voltage of the power supply end of the third target module at the output end of the third voltage detection module; the second input end of the control module is electrically connected to the output end of the second voltage detection module. The control module is configured to determine the working state of the second target module according to the second level signal; the second input end of the control module is electrically connected to the output end of the second voltage detection module. The control module is configured to determine the working state of the second target module according to the second level signal.

[0083] 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 outlet blade module; the third target module is any one of the powder supply roller module, the developing roller module, and the powder outlet blade module; and the first target module, the second target module, and the third target module are different modules.

[0084] 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 outlet blade module, by detecting the states of any two of the circuits through the two-way voltage detection circuit, the state of the third circuit can be inferred.

[0085] Specifically, in a possible implementation, the open circuit detection circuit further includes a second voltage detection module or a third voltage detection module.

[0086] It can be understood 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, 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, thereby realizing precise detection of the open circuit fault component.

[0087] Furthermore, for the convenience of understanding, the embodiments of the present application provide a circuit schematic diagram in which the first voltage detection module, the second voltage detection module, and the third voltage detection module all participate in circuit detection. Specifically, see Figure 7 , which provides a circuit schematic diagram of multi-channel detection for the embodiments of the present application. As Figure 7 shown, in Figure 5Based on this, it further 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.

[0088] Specifically, the circuit connections are as follows: The first end of the second diode is electrically connected to the output end of the high-voltage generation circuit module; the second end of the second diode is electrically connected to the power supply end of the second target module; the first end of the second optocoupler is electrically connected to the first end of the second diode; the second end of the second optocoupler is electrically connected to the second end of the second diode; the third end of the second optocoupler is grounded; the first end of the sixth resistor is electrically connected to the fourth end of the second optocoupler; the second end of the sixth resistor is electrically connected to the voltage source; the first end of the third diode is electrically connected to the output end of the high-voltage generation circuit module; the second end of the third diode is electrically connected to the power supply end 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 first end of the seventh resistor is electrically connected to the fourth end of the third optocoupler; the second end of the seventh resistor is electrically connected to the voltage source.

[0089] It should be noted that the node between the sixth resistor and the second optocoupler is electrically connected to the second input end of the control module, and the node between the sixth resistor and the second optocoupler is the output end of the first voltage detection module. The node between the seventh resistor and the third optocoupler is electrically connected to the third input end of the control module, and the node between the seventh resistor and the third optocoupler is the output end of the first voltage detection module.

[0090] Of course, as described above, in combination with 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 achieve the detection of each of the DR module, the SR module, and the DB module.

[0091] Of course, in a possible implementation manner, when the open-circuit detection circuit includes the second voltage detection module and / or the third voltage detection module, the open-circuit detection circuit correspondingly includes the second filtering module and / or the third filtering module. Specifically, the input end of the second filtering module is electrically connected to the output end of the second voltage detection module; the output end of the second filtering module is electrically connected to the second input end of the control module; the input end of the third filtering module is electrically connected to the output end of the third voltage detection module, and the output end of the third filtering module is electrically connected to the third input end of the control module.

[0092] It can be understood that the second filtering module is used to filter the interference signals in the second level signal and send the filtered second level signal to the control module; the third filtering module is used to filter the interference signals in the third level signal and send the filtered third level signal to the control module. Finally, the control module can detect the second target module and the third target module more accurately.

[0093] In a possible implementation, both the second filtering module and the third filtering module are RC filtering modules. Of course, the second filtering module and the third filtering module can also be other filtering circuits, and the present application does not make specific limitations thereto.

[0094] In practical applications, the control module may not have three idle input terminals. To address this problem, the circuit structures of the first voltage detection module, the second voltage detection module, and the third voltage detection module can be adjusted so that the detection of each of the DR module, the SR module, and the DB module can be achieved through an output terminal of a control module.

[0095] In a possible implementation, when there are three voltage detection modules for detecting the DR module, the SR module, and the DB module in the open - circuit detection circuit at the same time, different voltages can be set to represent the disconnection of different modules. Specifically, refer to Figure 8 , which provides another circuit schematic diagram for multi - path detection in the embodiments of the present application. As Figure 8 shown, the figure shows: the first diode D1, the first optocoupler Q1, the eighth resistor R8, the second diode D2, the second optocoupler Q2, the ninth resistor R9, the third diode D3, the third optocoupler Q3, the tenth resistor R10, and the eleventh resistor R11.

[0096] The specific circuit connection relationship is as follows: The first end of the first diode is used to be electrically connected to the output end of the high-voltage generation circuit module, and the second end of the first diode is used to be electrically connected to the power supply end of the first target module; The first end of the first optocoupler is electrically connected to the first end of the first diode; The second end of the first optocoupler is electrically connected to the second end of the first diode; The third end of the first optocoupler is grounded; The fourth end of the first optocoupler is electrically connected to the first end of the eighth resistor; The second end of the eighth resistor is electrically connected to the first input end of the control module; The first end of the second diode is used to be electrically connected to the output end of the high-voltage generation circuit module; The second end of the second diode is electrically connected to the power supply end of the second target module; The first end of the second optocoupler is electrically connected to the first end of the second diode; The second end of the second optocoupler is electrically connected to the second end of the second diode; 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 end of the control module; The first end of the third diode is electrically connected to the output end of the high-voltage generation circuit module; The second end of the third diode is electrically connected to the power supply end 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 resistor and the eleventh resistor is electrically connected to the first input end of the control module.

[0097] It can be understood that taking DC power supply as an example, when the first target module, the second target module, and the third target module are all normally conducting, the voltage of the first level signal is: (R8||R9||R10) / (R11+R8||R9||R10) VCC; When the second target module and the third target module are both normally conducting and the first target module is open, the voltage of the first level signal is: (R9||R10) / (R11+R8||R9||R10) VCC; When the first target module and the third target module are both normally conducting and the second target module is open, the voltage of the first level signal is: (R8||R10) / (R11+R8||R9||R10) VCC; When the second target module and the first target module are both normally conducting and the second target module is open, the voltage of the first level signal is: (R8||R9) / (R11+R8||R9||R10) VCC.

[0098] Of course, in the DR module, SR module, and DB module, any two modules or all three modules may fail simultaneously. It is understandable that the corresponding output voltages are also different. For the sake of brevity, this application will not elaborate on this here.

[0099] In practical applications, by adjusting the connection method of the optocoupler circuit, it is also possible to detect whether the DR module, SR module, and DB module are open-circuited. Specifically, in one possible implementation, refer to Figure 9 , which provides another circuit schematic diagram for multi-channel detection in the embodiments of this application. As Figure 9 shown, the figure shows: 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.

[0100] The specific circuit connection relationship is as follows: the first end of the first diode is electrically connected to the output end of the high-voltage generation circuit module, and the second end of the first diode is electrically connected to the power supply end of the first target module; the first end of the optocoupler is electrically connected to the first end of the first diode, the second end of the first optocoupler is electrically connected to the second end of the first diode, and the third end of the first optocoupler is grounded; the first end of the second diode is electrically connected to the output end of the high-voltage generation circuit module, and the second end of the second diode is used to be electrically connected to the power supply end of the second target module; the first end of the second optocoupler is electrically connected to the first end of the second diode, the second end of the second optocoupler is electrically connected to the second end of the second diode, and the third end of the second optocoupler is electrically connected to the fourth end of the first optocoupler; the first end of the third diode is electrically connected to the output end of the high-voltage generation circuit module, and the second end of the third diode is electrically connected to the power supply end 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 electrically connected to the fourth end of the first optocoupler, and the fourth end of the third optocoupler is electrically connected to the first input end of the control module.

[0101] It is understandable that taking DC power supply as an example, when the first target module, the second target module, and the third target module are all normally conducting, the voltage of the first level signal is low level; when any one of the first target module, the second target module, and the third target module is open-circuited, the voltage of the first level signal is high level.

[0102] Corresponding to the above embodiments, this application also provides an open-circuit detection chip, which includes any one of the open-circuit detection circuits described above. For the specific functions, refer to the above. For the sake of brevity, this application will not elaborate.

[0103] In the embodiments of the present application, "at least one" means one or more, and "a plurality of" means two or more. "And / or" describes the association relationship of associated objects and indicates that there can be three relationships. For example, A and / or B can represent the cases of A existing alone, A and B existing simultaneously, and B existing alone. Where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one of the following" and its similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, and c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple.

[0104] Those of ordinary skill in the art can realize that the various units and algorithm steps described in the embodiments disclosed herein can be implemented by a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0105] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0106] In several embodiments provided by the present application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or a part of this 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 for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM for short), random access memory (RAM for short), magnetic disks, or optical discs that can store program codes.

[0107] The same or similar parts among the various embodiments in this specification can be referred to each other. In particular, for the device embodiments and terminal embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the descriptions in the method embodiments.

Claims

1. An open circuit detection circuit, characterized in that: Applied to an image forming device, the high voltage generating circuit module in the image forming device is used to supply power to a powder supply roller module, a developing roller module and a powder discharge knife module respectively, and the circuit comprises: A first voltage detection module, wherein a detection end of the first voltage detection module is used to be electrically connected to a power supply end of a first target module, the first voltage detection module is used to detect a voltage at the power supply end of the first target module, and output a first level signal corresponding to the voltage at the power supply end of the first target module at an output end of the first voltage detection module; a control module, wherein a first input terminal of the control module is electrically connected to an output terminal of the first voltage detection module, and the control module is used to determine a working state of the first target module according to the first level signal; Wherein, 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 an abnormal state and a normal state.

2. The open circuit detection circuit according to claim 1, characterized in that: Also includes: A second voltage detection module and / or a third voltage detection module; The detection end of the second voltage detection module is used to be electrically connected to the power supply end of the second target module, and the second voltage detection module is used to detect the voltage of the power supply end of the second target module, and output a second level signal corresponding to the voltage of the power supply end of the second target module at the output end of the second voltage detection module; The detection end of the third voltage detection module is used to be electrically connected to the power supply end of the third target module, and the third voltage detection module is used to detect the voltage of the power supply end of the third target module, and output a third level signal corresponding to the voltage of the power supply end of the third target module at the output end of the third voltage detection module; The second input end of the control module is electrically connected to the output end of the second voltage detection module, and the control module is used to determine the working state of the second target module according to the second level signal; the second input end of the control module is electrically connected to the output end of the second voltage detection module, and the control module is used to determine the working state of the second target module according to the second level signal; Among them, the second target module is any one of the powder supply roller module, the developing roller module and the powder outlet knife module; the third target module is any one of the powder supply roller module, the developing roller module and the powder outlet knife 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: A first filtering module, wherein the input end of the first filtering module is electrically connected to the output end of the first voltage detection module, the output end of the first filtering module is electrically connected to the first input end of the control module, and the first filtering module is used to filter the interference signal 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: A second filtering module and / or a third filtering module; The input end of the second filtering module is electrically connected to the output end of the second voltage detection module, the output end of the second filtering module is electrically connected to the second input end of the control module, and the second filtering module is used to filter the interference signal in the second level signal and send the filtered second level signal to the control module; The input end of the third filter module is electrically connected to the output end of the third voltage detection module, and the output end of the third filter module is electrically connected to the third input end of the control module. The third filter module is used to filter the interference signal 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, wherein the input end of the level correction module is electrically connected to the output end of the first voltage detection module, the output end of the level correction module is electrically connected to the first input end of the control module, and 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 end 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, wherein a first end of the first resistor is used to be electrically connected to an output end of the high voltage generating circuit module, and a second end of the first resistor is used to be electrically connected to a power supply end of the first target module; a first optical coupler, wherein a first end of the first optical coupler is electrically connected to a first end of the first resistor, a second end of the first optical coupler is electrically connected to a second end of the first resistor, and a third end of the first optical coupler is grounded; a second resistor, wherein a first end of the second resistor is electrically connected to the fourth end of the first optical coupler, and a second end of the second resistor is electrically connected to a voltage source; The node between the second resistor and the first optical coupler is electrically connected to the first input terminal of the control module, and the node between the second resistor and the first optical coupler 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 used to be electrically connected to an output end of the high voltage generating circuit module, and a second end of the first diode is used to be electrically connected to a power supply end of the first target module; a first optical coupler, wherein a first end of the first optical coupler is electrically connected to a first end of the first diode, a second end of the first optical coupler is electrically connected to a second end of the first diode, and a third end of the first optical coupler is grounded; a second resistor, wherein a first end of the second resistor is electrically connected to the fourth end of the first optical coupler, and a second end of the second resistor is electrically connected to a voltage source; The node between the second resistor and the first optical coupler is electrically connected to the first input terminal of the control module, and the node between the second resistor and the first optical coupler 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: a first optical coupler, wherein a first end of the first optical coupler is used to be electrically connected to an output end of the high voltage generating circuit module, a second end of the first optical coupler is used to be electrically connected to a power supply end of the first target module, and a third end of the first optical coupler is grounded; a second resistor, wherein a first end of the second resistor is electrically connected to the fourth end of the first optical coupler, and a second end of the second resistor is electrically connected to a voltage source; The node between the second resistor and the first optical coupler is electrically connected to the first input terminal of the control module, and the node between the second resistor and the first optical coupler 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: a third resistor, a first end of the third resistor being electrically connected to an output end of the first voltage detection module; a first capacitor, wherein a first end of the first capacitor is electrically connected to a second end of the third resistor, and a second end of the first capacitor is grounded; Among them, the node between the third resistor and the first capacitor is electrically connected to the first input end of the control module, the node between the third resistor and the first capacitor is the output end of the first filtering module; the first end of the third resistor is the input end of the first filtering module.

10. The open circuit detection circuit according to claim 5, characterized in that: The level correction module specifically includes: A transistor, wherein the base of the transistor is electrically connected to the output end of the first voltage detection module, and the emitter of the transistor is grounded; a fourth resistor, wherein a first end of the fourth resistor is electrically connected to the base of the transistor, and a second end of the fourth resistor is electrically connected to the emitter of the transistor; a fifth resistor, wherein a first end of the fifth resistor is electrically connected to a voltage source, and a second end of the fifth resistor is electrically connected to a collector of the transistor; Among them, the node between the fifth resistor and the transistor is electrically connected to the first input end of the control module, the node between the fifth resistor and the transistor is the output end of the level correction module, and the base of the transistor is the input end 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: a second diode, wherein a first end of the second diode is used to be electrically connected to an output end of the high voltage generating circuit module, and a second end of the second diode is used to be electrically connected to a power supply end of the second target module; a second optical coupler, wherein a first end of the second optical coupler is electrically connected to a first end of the second diode, a second end of the second optical coupler is electrically connected to a second end of the second diode, and a third end of the second optical coupler is grounded; a sixth resistor, wherein a first end of the sixth resistor is electrically connected to the fourth end of the second optical coupler, and a second end of the sixth resistor is electrically connected to a voltage source; The node between the sixth resistor and the second optical coupler is electrically connected to the second input terminal of the control module, and the node between the sixth resistor and the second optical coupler 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: a third diode, wherein a first end of the third diode is used to be electrically connected to the output end of the high voltage generation circuit module, and a second end of the third diode is used to be electrically connected to the power supply end of the third target module; a third optical coupler, wherein a first end of the third optical coupler is electrically connected to a first end of the third diode, a second end of the third optical coupler is electrically connected to a second end of the third diode, and a third end of the third optical coupler is grounded; a seventh resistor, wherein a first end of the seventh resistor is electrically connected to the fourth end of the third optical coupler, and a second end of the seventh resistor is electrically connected to a voltage source; The node between the seventh resistor and the third optical coupler is electrically connected to the third input terminal of the control module, and the node between the seventh resistor and the third optical coupler 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 switch 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 used to be electrically connected to an output end of the high voltage generating circuit module, and a second end of the first diode is used to be electrically connected to a power supply end of the first target module; a first optical coupler, wherein a first end of the first optical coupler is electrically connected to a first end of the first diode, a second end of the first optical coupler is electrically connected to a second end of the first diode, and a third end of the first optical coupler is grounded; an eighth resistor, wherein the fourth end of the first optical coupler is electrically connected to the first end of the eighth resistor, and the second end of the eighth resistor is electrically connected to the first input end of the control module; a second diode, wherein a first end of the second diode is used to be electrically connected to an output end of the high voltage generating circuit module, and a second end of the second diode is used to be electrically connected to a power supply end of the second target module; a second optical coupler, wherein a first end of the second optical coupler is electrically connected to a first end of the second diode, a second end of the second optical coupler is electrically connected to a second end of the second diode, and a third end of the second optical coupler is grounded; a ninth resistor, wherein the fourth end of the second optical coupler is electrically connected to the first end of the ninth resistor, and the second end of the ninth resistor is electrically connected to the first input end of the control module; a third diode, wherein a first end of the third diode is used to be electrically connected to the output end of the high voltage generation circuit module, and a second end of the third diode is used to be electrically connected to the power supply end of the third target module; a third optical coupler, wherein a first end of the third optical coupler is electrically connected to a first end of the third diode, a second end of the third optical coupler is electrically connected to a second end of the third diode, and a third end of the third optical coupler is grounded; a tenth resistor, wherein the fourth end of the third optical coupler is electrically connected to the first end of the tenth resistor; an eleventh resistor, a first end of the eleventh resistor being electrically connected to the power supply; a second end of the eleventh resistor being electrically connected to a second end of the tenth resistor, and a node between the tenth resistor and the eleventh resistor being electrically connected to a first input end of the control module.

14. The open circuit detection circuit according to claim 2, characterized in that: When the switch 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 used to be electrically connected to an output end of the high voltage generating circuit module, and a second end of the first diode is used to be electrically connected to a power supply end of the first target module; a first optical coupler, wherein a first end of the first optical coupler is electrically connected to a first end of the first diode, a second end of the first optical coupler is electrically connected to a second end of the first diode, and a third end of the first optical coupler is grounded; a second diode, wherein a first end of the second diode is used to be electrically connected to an output end of the high voltage generating circuit module, and a second end of the second diode is used to be electrically connected to a power supply end of the second target module; a second optical coupler, wherein a first end of the second optical coupler is electrically connected to a first end of the second diode, a second end of the second optical coupler is electrically connected to a second end of the second diode, and a third end of the second optical coupler is electrically connected to a fourth end of the first optical coupler; a third diode, wherein a first end of the third diode is used to be electrically connected to the output end of the high voltage generation circuit module, and a second end of the third diode is used to be electrically connected to the power supply end of the third target module; A third optocoupler, wherein 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 electrically connected to the fourth end of the first optocoupler, and the fourth end of the third optocoupler is electrically connected to the first input end of the control module.

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

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