Abnormality detection circuit, high-voltage board, and imaging device

Abstract

The embodiment of the invention provides an anomaly detection circuit, a high-voltage board and an imaging device. The anomaly detection circuit comprises an anomaly detection module and a signal processing module, the anomaly detection module is connected with the high-voltage power supply module, and the anomaly detection module is used for detecting whether multiple paths of output voltages output by the high-voltage power supply module are abnormal or not and generating detection signals corresponding to each path of output voltage; the signal processing module is connected with the anomaly detection module and the main control module, the signal processing module is used for sending a positioning signal to the main control module when the detection signal corresponding to the at least one path of output voltage represents that the output voltage is abnormal, and the positioning signal is used for representing that the abnormal output voltage exists in the multiple paths of output voltage. According to the invention, the signal processing module processes the detection signals of the multi-path output voltage abnormity to generate the positioning signals, the abnormity position is determined through the positioning signals, and the abnormity position can be identified only through one communication interface.

Description

Technical Field

[0001] The present application relates to the field of imaging technology, and in particular to an abnormality detection circuit, a high-voltage board and an imaging device. Background Art

[0002] The charging, developing, and transfer processes of laser printing require different high-voltage amplitudes (mostly DC high voltage, but there are also AC high voltage output specifications). In the existing technology, the main controller (SoC) usually outputs a low-voltage control signal to the high-voltage board. After conversion by modules such as the drive amplifier circuit, oscillation circuit, and voltage-doubling rectifier circuit, the high-voltage board finally outputs different high voltages to the corresponding high-voltage loads (photosensitive drums, developing rollers, transfer rollers, and other devices).

[0003] In the high-voltage imaging solution, in order to avoid damage to the hardware caused by output abnormalities under extreme conditions, some hardware protection solutions for overcurrent protection and overvoltage protection (hereinafter collectively referred to as abnormal protection) are often configured inside the high-voltage board. However, when the number of high-voltage generation loops on the high-voltage board increases, theoretically, the corresponding protection circuits for different high voltages will also increase, and the corresponding interface signals used to protect circuit signal transmission will also increase. This will greatly increase the occupation of data board interface resources, and the large increase in interface configuration will also put forward higher requirements on CPU resource consumption and circuit board wiring, and is not conducive to the simplified design requirements of interface design. If the output end of all abnormal protection signals is represented by a common abnormal output pin, although the number of interface signals can be reduced, the output level of the abnormal signal determines whether there are two situations of abnormality on the high-voltage board / abnormality does not occur, but when the high-voltage abnormality occurs, it is impossible to accurately locate the high-voltage position of the abnormality in time, which brings great inconvenience to maintenance and test personnel to locate the problem point and make targeted repairs.

[0004] In summary, using different interfaces to indicate the abnormalities of each high voltage can clearly and intuitively locate the problem, but it is easy to cause consumption of hardware design resources; if a single fault output interface is used, the data board cannot accurately determine the high voltage location where the abnormality occurs. Summary of the invention

[0005] The embodiments of the present application provide an abnormality detection circuit, a high-voltage board and an imaging device, so as to timely and accurately determine the high-voltage position where the abnormality occurs and save resources.

[0006] In a first aspect, an embodiment of the present application provides an abnormality detection circuit, including: an abnormality detection module and a signal processing module;

[0007] The abnormality detection module is connected to the high-voltage power supply module, and is used to detect whether there are abnormalities in the multiple output voltages output by the high-voltage power supply module, and to generate a detection signal corresponding to each output voltage;

[0008] The signal processing module is connected to the abnormality detection module and the main control module respectively. The signal processing module is used to send a positioning signal to the main control module when the detection signal corresponding to at least one output voltage indicates that the output voltage is abnormal. The positioning signal is used to indicate that there is an abnormal output voltage in the multiple output voltages.

[0009] In one of the embodiments, the signal processing module includes: a processing unit and an analog-to-digital conversion unit;

[0010] One end of the processing unit is connected to the abnormality detection module, and the other end of the processing unit is connected to the analog-to-digital conversion unit;

[0011] The processing unit is used to generate a first signal after processing at least one abnormal signal; the abnormal signal is a detection signal indicating that the output voltage is abnormal;

[0012] The analog-to-digital conversion unit is used to convert the first signal into a positioning signal, wherein the positioning signal includes a duty cycle characteristic.

[0013] In one embodiment, the signal processing module includes: a processing unit and a limiting unit, one end of the processing unit is connected to the abnormality detection module, and the other end of the processing unit is connected to the limiting unit;

[0014] The processing unit is used to generate a first signal after processing at least one abnormal signal; the abnormal signal is a detection signal indicating that the output voltage is abnormal;

[0015] The limiting unit is used to limit the first signal to generate a positioning signal, wherein the positioning signal includes a voltage value feature.

[0016] In one embodiment, the processing unit includes: a plurality of voltage dividing subunits and an operation subunit, wherein a first end of the voltage dividing subunit is connected to the abnormality detection module, a second end of the voltage dividing subunit is connected to a first input end of the operation subunit, and a second input end of the operation subunit is grounded;

[0017] The voltage divider unit is used to generate a corresponding reference voltage according to the abnormal signal; the operation unit is used to accumulate the reference voltages and generate a first signal.

[0018] In one of the embodiments, the abnormality detection circuit further includes an interface unit, and the interface unit is used to connect to the main control module and output a positioning signal to the main control module.

[0019] In one of the embodiments, the analog-to-digital conversion unit is a pulse width modulation unit, and the pulse width modulation unit includes a comparator and a triangular wave generator;

[0020] A first input terminal of the comparator is connected to the output terminal of the processing unit, and a second input terminal of the comparator is connected to the triangular wave generator;

[0021] The triangle wave generator is used to generate a triangle wave signal;

[0022] The comparator is used for synthesizing the first signal and the triangular wave signal into a positioning signal.

[0023] In one of the embodiments, the abnormality detection circuit further includes an interface unit having an ADC function, and the interface unit is used to connect to the main control module and output a positioning signal to the main control module.

[0024] In one of the embodiments, the abnormality detection module includes a plurality of abnormality detection units, and the abnormality detection units are connected to the high-voltage power supply module;

[0025] The abnormality detection unit is used to output a high-level detection signal when an abnormality in the output voltage is detected;

[0026] When it is detected that the output voltage is normal, a low-level detection signal is output.

[0027] In one embodiment, the limiting unit includes a Zener diode and a capacitor, a first end of the Zener diode is connected to the processing unit, a second end of the Zener diode is grounded, and the capacitor is connected in parallel to the Zener diode.

[0028] In a second aspect, an embodiment of the present application further provides a high-voltage board, comprising any of the above-mentioned abnormality detection circuits and a high-voltage power supply module.

[0029] In one of the embodiments, the high-voltage power supply module includes a plurality of high-voltage generating units, and the output end of the high-voltage generating unit is connected to the abnormality detection module for generating an output voltage and outputting the output voltage to the abnormality detection module.

[0030] In a third aspect, an embodiment of the present application provides an imaging device, comprising any of the above-mentioned high-voltage boards and a main control module connected thereto;

[0031] The main control module is used to determine the presence of an abnormal high-voltage generating unit on the high-voltage board according to the positioning signal output by the high-voltage board.

[0032] An abnormality detection circuit, a high-voltage board, and an imaging device provided in an embodiment of the present application, the abnormality detection circuit includes: an abnormality detection module and a signal processing module; the abnormality detection module is connected to the high-voltage power supply module, the abnormality detection module is used to detect whether there is an abnormality in the multi-channel output voltage output by the high-voltage power supply module, and generate a detection signal corresponding to each output voltage; the signal processing module is respectively connected to the abnormality detection module and the main control module, the signal processing module is used to send a positioning signal to the main control module when the detection signal corresponding to at least one output voltage indicates that the output voltage is abnormal, and the positioning signal is used to indicate that there is an abnormal output voltage in the multi-channel output voltage. The present application generates a positioning signal by processing the detection signal of the abnormal multi-channel output voltage through the signal processing module, and determines the location of the abnormality through the positioning signal. The present application only needs one communication interface to identify the location where the abnormality occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0034] Figure 1 A schematic diagram of the structure of an abnormality detection circuit provided in one embodiment of the present application;

[0035] Figure 2 An internal schematic diagram of an abnormality detection circuit provided in an embodiment of the present application;

[0036] Figure 3 A schematic diagram of the circuit structure of a processing unit provided in one embodiment of the present application;

[0037] Figure 4 A schematic diagram of the circuit structure of an analog-to-digital conversion unit provided in one embodiment of the present application;

[0038] Figure 5 A schematic diagram of the circuit structure of a triangle wave generator provided in one embodiment of the present application;

[0039] Figure 6 A schematic diagram of the circuit structure of a signal processing module provided in another embodiment of the present application.

[0040] Reference numerals:

[0041] 100, main control module; 200, high voltage board; 210, high voltage power supply module; 220, abnormality detection circuit; 221, abnormality detection module; 222, signal processing module; 310, processing unit; 320, analog-to-digital conversion unit; 311, first voltage divider subunit; 312, second voltage divider subunit; 313, third voltage divider subunit; 314, operation subunit.

[0042] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0043] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0044] In the high-voltage imaging solution, in order to avoid damage to the hardware caused by output abnormalities under extreme conditions, some hardware protection solutions for overcurrent protection and overvoltage protection (hereinafter collectively referred to as abnormal protection) are often configured inside the high-voltage board. However, when the number of high-voltage generation loops on the high-voltage board increases, theoretically, the corresponding protection circuits for different high voltages will also increase, and the corresponding interface signals used to protect circuit signal transmission will also increase. This will greatly increase the occupation of data board interface resources, and the large increase in interface configuration will also put forward higher requirements on CPU resource consumption and circuit board wiring, and is not conducive to the simplified design requirements of interface design. If the output end of all abnormal protection signals is represented by a common abnormal output pin, although the number of interface signals can be reduced, the output level of the abnormal signal determines whether there are two situations of abnormality on the high-voltage board / abnormality does not occur, but when the high-voltage abnormality occurs, it is impossible to accurately locate the high-voltage position of the abnormality in time, which brings great inconvenience to maintenance and test personnel to locate the problem point and make targeted repairs.

[0045] In summary, using different interfaces to indicate the abnormalities of each high voltage can clearly and intuitively locate the problem, but it is easy to cause consumption of hardware design resources; if a single fault output interface is used, the data board cannot accurately determine the high voltage location where the abnormality occurs.

[0046] An abnormality detection circuit provided by an embodiment of the present application includes: an abnormality detection module and a signal processing module; the abnormality detection module is connected to the high-voltage power supply module, and the abnormality detection module is used to detect whether there is an abnormality in the multi-channel output voltage output by the high-voltage power supply module, and generate a detection signal corresponding to each output voltage; the signal processing module is respectively connected to the abnormality detection module and the main control module, and the signal processing module is used to send a positioning signal to the main control module when the detection signal corresponding to at least one output voltage indicates that the output voltage is abnormal, and the positioning signal is used to indicate that there is an abnormal output voltage in the multi-channel output voltage. In the present application, the detection signal of the abnormal multi-channel output voltage is processed by the signal processing module to generate a positioning signal, and the location of the abnormality is determined by the positioning signal. The present application only needs one communication interface to identify the location where the abnormality occurs.

[0047] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0048] like Figure 1 As shown, Figure 1 The present invention is a structural schematic diagram of an abnormality detection circuit provided in an embodiment of the present application, wherein the abnormality detection circuit comprises: an abnormality detection module 221 and a signal processing module 222; the abnormality detection module 221 is connected to the high-voltage power supply module 210, and the abnormality detection module 221 is used to detect whether there is an abnormality in the multiple output voltages output by the high-voltage power supply module 210, and generate a detection signal corresponding to each output voltage; the signal processing module 222 is respectively connected to the abnormality detection module 221 and the main control module 100, and the signal processing module 222 is used to send a positioning signal to the main control module 100 when the detection signal corresponding to at least one output voltage indicates that the output voltage is abnormal, and the positioning signal is used to indicate that there is an abnormal output voltage in the multiple output voltages.

[0049] Specifically, the main control module 100 sends a PWM signal to the high-voltage power supply module 210, and the high-voltage power supply module 210 outputs the corresponding high voltage according to the PWM signal, wherein the high-voltage power supply module 210 may include multiple high-voltage generation units to output different high-voltage values ​​according to demand. The abnormality detection module 221 is connected to the high-voltage power supply module 210, and is responsible for detecting whether there is an abnormality in the voltage output by the high-voltage power supply module 210, and generating a corresponding detection signal for each output voltage. The signal processing module 222 generates a positioning signal by processing the detection signal characterizing the output voltage abnormality. The main control module 100 can quickly and accurately locate the problem voltage and circuit according to the positioning signal to ensure the stability and safety of the system. In this application, the detection signal of the abnormal output voltage of multiple channels is processed by the signal processing module 222 to generate a positioning signal, and the location of the abnormality is determined by the positioning signal, and only one communication interface is required to identify the location where the abnormality occurs.

[0050] In one embodiment, the abnormality detection module 221 includes multiple abnormality detection units, which are connected to the high-voltage power supply module 210; the abnormality detection unit is used to output a high-level detection signal when the output voltage is detected to be abnormal; and output a low-level detection signal when the output voltage is detected to be normal.

[0051] When the high-voltage power supply module 210 includes multiple high-voltage generating units, each high-voltage generating unit is independent and does not interfere with each other. Taking the first high-voltage generating unit as an example, the abnormality detection module 221 collects the output voltage of the first high-voltage generating unit by means of resistor voltage division or current collection. If the abnormality detection module 221 detects that the voltage output by the first high-voltage generating unit is normal, it outputs a low level; if it detects that the voltage output by the first high-voltage generating unit is abnormal, it outputs a high level. There are many situations in which the output voltage of the high-voltage generating unit is abnormal, for example, high-voltage overcurrent abnormality will cause the output voltage of the high-voltage generating unit to be abnormal.

[0052] In one embodiment, the abnormality detection circuit 220 further includes an interface unit, and the interface unit is used to connect to the main control module 100 and output a positioning signal to the main control module 100 .

[0053] In one embodiment, if Figure 2 As shown, Figure 2The internal schematic diagram of the abnormality detection circuit 220 provided in one embodiment of the present application. The signal processing module 222 includes: a processing unit 310 and an analog-to-digital conversion unit 320; one end of the processing unit 310 is connected to the abnormality detection module 221, and the other end of the processing unit 310 is connected to the analog-to-digital conversion unit 320; the processing unit 310 is used to generate a first signal after processing at least one abnormal signal; the abnormal signal is a detection signal characterizing the abnormality of the output voltage; the analog-to-digital conversion unit 320 is used to convert the first signal into a positioning signal, wherein the positioning signal includes a duty cycle feature.

[0054] In one embodiment, the processing unit 310 includes: multiple voltage divider subunits and an operation subunit 314, the first end of the voltage divider subunit is connected to the abnormality detection module 221, the second end of the voltage divider subunit is connected to the first input end of the operation subunit 314, and the second input end of the operation subunit 314 is grounded; the voltage divider subunit is used to generate a corresponding reference voltage according to the abnormal signal; the operation subunit 314 is used to accumulate the reference voltage and generate a first signal.

[0055] Figure 2 The embodiment of the invention is described by taking three voltage-dividing subunits as an example. The voltage-dividing subunits are used to receive the detection signal output by the abnormality detection module 221, and convert it into three different reference input voltages through the internal RC resistor-capacitor voltage-dividing network, so as to achieve the differentiation of the alarm signal. The first detection signal, the second detection signal and the third detection signal are divided and processed to generate reference voltages only when the output voltage of the high-voltage generating unit to which they belong is abnormal, that is, the voltage-dividing subunit records the first detection signal as the first reference voltage Vref_1 after voltage-dividing processing; the voltage-dividing subunit records the second detection signal as the second reference voltage Vref_2 after voltage-dividing processing; the voltage-dividing subunit records the third detection signal as the third reference voltage Vref_3 after voltage-dividing processing. When the output voltage of the three high-voltage generating units is normal, the detection signal is at a low level, and when the output voltage is abnormal, the detection signal is at a high level. Among them, if only the output voltage of the first high-voltage generating unit is detected to be abnormal, when the first detection signal is high level (3.3V) (assuming that the high level represents 3.3V), the voltage divider unit generates the first reference voltage corresponding to the first detection signal, at which time the second reference voltage Vref_2 and the third reference voltage Vref_3 are both 0, and the first signal is output after calculation by the operation subunit 314, and the first signal is a stable level a. The first signal is output as a positioning signal through the analog-to-digital conversion unit 320, and the positioning signal is a PWM wave. The main control module 100 can determine the location of the abnormality by using the duty cycle characteristics of the positioning signal.

[0056] In one embodiment, if Figure 2As shown, the analog-to-digital conversion unit 320 is a pulse width modulation unit, which includes a comparator and a triangular wave generator; the first input end of the comparator is connected to the output end of the processing unit 310, and the second input end of the comparator is connected to the triangular wave generator; the triangular wave generator is used to generate a triangular wave signal; the comparator is used to synthesize the first signal and the triangular wave signal into a positioning signal.

[0057] Specifically, the first signal is input to the first input terminal (non-inverting input terminal) of the comparator, and the second input terminal (inverting input terminal) of the comparator is directly connected to the triangular wave generator, wherein the triangular wave generator finally outputs a triangular wave signal with a certain frequency and an amplitude of 0-3.3V through its internal RC oscillation. According to the voltage comparison principle of the non-inverting input terminal and the inverting input terminal, the comparator outputs a high level if the voltage of the non-inverting input terminal is greater than the voltage of the inverting input terminal; when the voltage of the inverting input terminal of the comparator is higher than the voltage of the non-inverting input terminal, the comparator outputs a low level. If the first signal is a stable level a, when the voltage of level a is higher than the triangular wave voltage, the output is high, otherwise it is output low. The positioning signal output by the final comparator is a voltage waveform, that is, the positioning signal received by the main control module 100 is a PWM waveform with a certain frequency and different duty cycles, as shown in Table 1 below. The output voltage (first signal) of the operator unit 314 is adjustable, and the first signal is related to the first detection signal, the second detection signal and the third detection signal, so the positioning signal output by the comparator is a PWM waveform with a constant frequency but a variable duty cycle. The PWM waveform is input to the main control module 100, and the main control module 100 can analyze whether each high-voltage generating unit on the high-voltage board 200 is abnormal and the location of the abnormality.

[0058] Table 1 Waveform state diagram of positioning signal in one embodiment

[0059]

[0060] When there are three high-voltage generating units on the high-voltage board 200 that require feedback of abnormal conditions, the abnormality detection circuit 220 can realize separate alarms when each high-voltage generating unit is abnormal, and can also enable the main control module 100 to identify the abnormal conditions of multiple high-voltage generating units by positioning the duty cycle characteristics of the signal.

[0061] When the output of each high-voltage generating unit on the high-voltage board 200 is normal, that is, the first detection signal Vref_1, the second detection signal Vref_2, and the third detection signal Vref_3 are all low-level, the input end of the operator unit 314 is 0, and the positioning signal continues to output a low level. When one or more high-voltage generating units are abnormal (one of the above 7 alarm situations), the operator unit 314 is an adder, that is, the input end of the adder is the reference voltage of the three detection signals, and the adder will output a unique output voltage, namely the first signal (a certain level in ag), which is compared by the comparator in the analog-to-digital conversion unit 320, and the positioning signal will be output at the output end of the comparator, and the duty cycle characteristics of the positioning signal (a certain duty cycle % in AG). As mentioned above, because the output characteristics of the positioning signal are different when abnormal conditions occur in different high-voltage generating units, the duty cycle characteristics of the positioning signal can identify the abnormal state on the high-voltage board 200. The positioning signal is input to the main control module 100 through an interface. Even under the condition of only one interface control, a multi-channel and multi-state abnormal output alarm of the high-voltage generation unit can be realized.

[0062] To help understand the protection scheme and logic of the above patent proposal, this application explains the specific implementation method and principle of the hardware circuit through an embodiment. This embodiment describes the specific implementation method of the abnormality detection circuit 220.

[0063] like Figure 3 As shown, Figure 3A schematic diagram of the circuit structure of a processing unit 310 provided in an embodiment of the present application. The processing unit 310 includes: a plurality of voltage-dividing subunits and an operation subunit 314. In this embodiment, three detection signals are taken as an example. The first voltage-dividing subunit 311 includes a first resistor, a second resistor and a first capacitor. The first end of the first resistor is used to input the first detection signal. The first resistor is connected in series with the second resistor, and the second resistor and the first capacitor are connected in parallel. The second end of the first resistor is the output end of the first voltage-dividing subunit 311; the circuit connection mode of the second voltage-dividing subunit 312 and the third voltage-dividing subunit 313 is the same as that of the first voltage-dividing subunit 311. The second voltage-dividing subunit 312 includes a third resistor, a fourth resistor and a second capacitor, and the third voltage-dividing subunit 313 includes a fifth resistor, a sixth resistor and a third capacitor. The first voltage divider unit 311 generates a first reference voltage U1 after dividing the first detection signal, the second voltage divider unit 312 generates a second reference voltage U2 after dividing the second detection signal, and the third voltage divider unit 313 generates a third reference voltage U3 after dividing the third detection signal. The first reference voltage, the second reference voltage and the third reference voltage are input to the non-inverting input terminal of the operator unit 314. The operator unit 314 includes an adder, which is an analog circuit based on an operational amplifier unit to realize the addition of multiple reference voltages. The inverting input terminal of the adder is connected to the output terminal of the adder through a resistor. The operator unit 314 also includes a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor. The first reference voltage is input to the non-inverting input terminal of the adder through the seventh resistor, the second reference voltage is input to the non-inverting input terminal of the adder through the eighth resistor, and the third reference voltage is input to the non-inverting input terminal of the adder through the ninth resistor. The first end of the tenth resistor is connected to the non-inverting input terminal of the adder, and the second end of the tenth resistor is grounded. The operator unit 314 also includes an eleventh resistor, a twelfth resistor, and a thirteenth resistor, wherein the first end of the eleventh resistor is grounded, the second end of the eleventh resistor is connected to the inverting input end of the adder, the inverting input end of the adder is connected to the output end of the adder through the twelfth resistor and the thirteenth resistor, and the output end of the adder is connected to the analog-to-digital conversion unit 320.

[0064] Specifically, when the first detection signal, the second detection signal and the third detection signal are at a low level (0V), the high voltage generation unit is normal; if at least one of the first detection signal, the second detection signal and the third detection signal is at a high level (3.3V), it indicates that at least one high voltage generation unit is abnormal. Taking the first detection signal as an example, when the first detection signal is at a high level, the high level signal generates a first reference voltage U1 after voltage division by resistors R1 and R2. The three detection signals are divided by their respective voltage division subunits to generate reference voltages, and the first reference voltage U1, the second reference voltage U2 and the third reference voltage U3 are different.

[0065] In one embodiment, it is assumed that when the alarm is triggered, the voltage division of U1 is 0.3V; the voltage division of U2 is 0.4V; and the voltage division of U3 is 0.5V. Figure 3 As shown, for the convenience of calculation, the relevant resistors of the adder circuit are all configured as 2KΩ, among which R13 is configured as 4KΩ. The inverting input terminal of the adder is grounded through a resistor, and the voltage of the non-inverting terminal is set to Ux. According to the virtual short and virtual open principle of the op amp, the non-inverting input terminal of the adder is as shown in formula (1),

[0066] U1-Ux) / 2k+(U2-Ux) / 2k+(U3-Ux) / 2k= Ux / 2k Formula (1)

[0067] From formula (1), we can get: U1+U2+U3=4Ux

[0068] The inverting input terminal of the adder is shown in formula (2):

[0069] Ux / 2k=(Uo-Ux) / 6K Formula (2)

[0070] Among them, the output voltage of the adder is U0. Combining formulas (1) and (2), it can be concluded that U1+U2+U3=Uo, that is, the voltage addition principle is realized. When the three high-voltage generating units are abnormal at the same time, U1=0.3V, U2=0.4V, U3=0.5V, then it can be calculated that Uo=1.2V. Therefore, the reference voltages U1, U2, and U3 generated by the first detection signal, the second detection signal, and the third detection signal are different. In theory, the voltage values ​​of the first signal Uo formed by the three through permutation and combination are different, and the voltage value of the first signal is unique.

[0071] like Figure 4 As shown, Figure 4 The circuit structure diagram of the analog-to-digital conversion unit 320 provided in one embodiment of the present application. The analog-to-digital conversion unit 320 is a pulse width modulation unit, which includes a comparator and a triangular wave generator; the first input end of the comparator is connected to the output end of the processing unit 310, and the second input end of the comparator is connected to the triangular wave generator; the triangular wave generator is used to generate a triangular wave signal; the comparator is used to synthesize the first signal and the triangular wave signal into a positioning signal.

[0072] Specifically, the comparator is used to compare the voltage of the first signal of the adder operation result with the triangular wave signal output by the triangular wave, and output a positioning signal, which is a PWM waveform with a constant frequency and a variable and adjustable duty cycle, and the adjustment of the duty cycle mainly depends on the output result of the adder. The present application can realize that when the detection signals of three high-voltage generation units need to be fed back to the main control module 100, 7 PWM signals with different duty cycles can be generated through permutations and combinations, as shown in Table 1.

[0073] like Figure 5 As shown, Figure 5 A schematic diagram of the circuit structure of a triangular wave generator provided for an embodiment of the present application. For the convenience of calculation, all resistor values ​​are configured to be 10KΩ. Assuming +VDD=15V, -VDD=0V, the hardware principle analysis of the figure below is as follows: The circuit mainly relies on the charging and discharging of capacitor C101 to output a triangular wave voltage with a constantly changing voltage. When powered on for the first time, the voltage at the capacitor terminal of C101 is 0V. At this time, the voltage at the in-phase terminal of the comparator is higher than the voltage at the reverse terminal. The comparator outputs a high voltage of 15V. At this time, the voltage at Ua is about 10V according to Ohm's law. The voltage at the output terminal of the comparator charges the capacitor C101 through R105. When the voltage at the C101 terminal exceeds 10V, the comparator output flips to 0V. At this time, the voltage of C101 is discharged to the ground through R105, and the voltage continues to decrease. When the comparator output is 0V, it is equivalent to R102 and R104 being connected in parallel. At this time, the voltage at the in-phase terminal of the comparator is recorded as Ua', which is about 5V. That is, the voltage of capacitor C101 is continuously discharged through R105 until it is discharged from 10V to 5V, and the comparator is flipped again to charge C101. Such repeated actions finally realize the output of a 5V-10V oscillating waveform at the waveform output end. Although the overall charging and discharging of the capacitor presents a parabolic state (the entire waveform segment of 0-15V), if only the voltage waveform of the middle segment is intercepted, it can be approximately considered as a waveform that rises and falls in a straight line, that is, it can be approximately regarded as a triangular wave waveform. The voltage parameter of the triangular wave signal of this embodiment is 5-10V, wherein the voltage fluctuation range of the oscillating triangular wave can be adjusted by adjusting the circuit resistance and the voltage values ​​+VDD and -VDD. That is, a 0-3.3V triangular wave oscillation waveform can be generated by parameter modification in the end. In this embodiment, the frequency of the triangular wave can be appropriately changed by adjusting the capacitance of C101, and the capacitance of C101 can be set according to actual conditions, which is not limited in this application.

[0074] In one embodiment, if Figure 6 As shown, Figure 6 A schematic diagram of the circuit structure of a signal processing module 222 provided in another embodiment of the present application. The signal processing module 222 includes: a processing unit 310 and a limiting unit, one end of the processing unit 310 is connected to the abnormality detection module 221, and the other end of the processing unit 310 is connected to the limiting unit; the processing unit 310 is used to generate a first signal after processing at least one abnormal signal; the abnormal signal is a detection signal characterizing an abnormal output voltage; the limiting unit is used to generate a positioning signal after limiting the first signal, wherein the positioning signal includes a voltage value feature.

[0075] In one embodiment, the limiting unit includes a Zener diode and a capacitor, a first end of the Zener diode is connected to the processing unit 310, a second end of the Zener diode is grounded, and the capacitor is connected in parallel to the Zener diode.

[0076] In one embodiment, the abnormality detection circuit 220 further includes an interface unit, the interface unit has an ADC function, and the interface unit is used to connect to the main control module 100 and output a positioning signal to the main control module 100.

[0077] Specifically, the working principle of the processing unit 310 is as follows: Figure 3 As shown, this embodiment uses the amplitude of the adder output voltage as the characteristic discrimination basis of the positioning signal for distinction and judgment. The scheme of this embodiment requires that the positioning signal is input to the main control module 100 through the ADC interface, so that the main control module 100 can identify the voltage values ​​of different analog quantities according to the positioning signal.

[0078] The processing unit 310 of the abnormality detection circuit 220 and Figure 3 The circuit is consistent with that of the main control module 100, and the specific working principle is not described in detail here. After the first signal is accumulated by the adder, theoretically, 7 different voltage amplitudes of the positioning signal can be identified, and the positioning signal is transmitted through the ADC interface of the main control module 100. The main control module 100 identifies and reads the voltage value of the positioning signal through its internal ADC unit to determine and locate the abnormality of the high voltage generating unit in the high voltage board 200.

[0079] Table 2 Schematic diagram of waveform of positioning signal in another embodiment

[0080]

[0081] When the output of each high-voltage generating unit on the high-voltage board 200 is normal, that is, the first detection signal Vref_1, the second detection signal Vref_2, and the third detection signal Vref_3 are all low-level, the input end of the operator unit 314 is 0, and the positioning signal continues to output a low level. When one or more high-voltage generating units are abnormal (one of the above 7 alarm situations), the operator unit 314 is an adder, that is, the input end of the adder is the reference voltage of the three detection signals, and the adder will output a unique output voltage, namely the first signal (a certain level in ag), which is compared by the comparator in the analog-to-digital conversion unit 320, and the positioning signal will be output at the output end of the comparator, and the waveform amplitude of the positioning signal is a characteristic (a certain amplitude in A1-G1). As mentioned above, because the output characteristics of the positioning signal are different when abnormal conditions occur in different high-voltage generating units, the amplitude characteristics of the positioning signal can identify the abnormal state on the high-voltage board 200. The positioning signal is input to the main control module 100 through an interface. Even under the condition of only one interface control, a multi-channel and multi-state abnormal output alarm of the high-voltage generation unit can be realized.

[0082] Generally, the ADC interface of the main control module 100 has a limited input voltage range (for example: 0-3.3V or 0-1.8V), so it is necessary to ensure that the maximum output voltage (maximum amplitude of the abnormal voltage signal) superimposed by the adder does not exceed the allowable input voltage range of the ADC. Otherwise, the circuit of the main control module 100 may be damaged. Just in case, an output limiting circuit can be added to the output end of the adder circuit to ensure that the output signal does not exceed the allowable voltage range of the ADC.

[0083] In this embodiment, the output limiting circuit is represented by a voltage stabilizing diode, that is, the maximum value of the output voltage is stabilized by the clamping effect of the voltage stabilizing diode. The capacitor is used for smoothing and filtering.

[0084] The present application uses a single interface to realize abnormal feedback and transmission of multiple detection signals. Compared with the existing technology, it reduces costs and saves hardware design interface resources. Secondly, the present application is based on distinguishing different abnormal information transmission contents by identifying the duty cycle or amplitude of the PWM signal. It can be applied to scenarios where multiple high-voltage generation units monitor abnormalities at the same time, interface resources are limited, and the level changes of the monitoring signals are relatively single.

[0085] The present application also provides a high-voltage board 200, such as Figure 1 As shown, it includes any of the above-mentioned abnormality detection circuits 220 and a high-voltage power supply module 210.

[0086] In one embodiment, the high-voltage power supply module 210 includes a plurality of high-voltage generating units, and the output end of the high-voltage generating unit is connected to the abnormality detection module 221 for generating an output voltage and outputting the output voltage to the abnormality detection module 221 .

[0087] The present application embodiment provides an imaging device, such as Figure 1 As shown, it includes any of the above-mentioned high-voltage boards 200 and a main control module 100 connected thereto; the main control module 100 is used to determine whether there is an abnormal high-voltage generating unit on the high-voltage board 200 according to a positioning signal output by the high-voltage board 200.

[0088] In the above-mentioned embodiment, it should be understood that the main control module 100 can be a central processing unit 310 (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the invention can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor.

[0089] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (NVM), such as at least one disk storage.

[0090] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of this application is not limited to only one bus or one type of bus.

[0091] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special-purpose computer.

[0092] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (Application Specific Integrated Circuits, referred to as: ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0093] The division of units is only a logical function division, and there may be other divisions in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0094] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0095] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit 310, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0096] If the 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 invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0097] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0098] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. An abnormality detection circuit, characterized in that: include: Anomaly detection module and signal processing module; The abnormality detection module is connected to the high-voltage power supply module, and is used to detect whether there is an abnormality in the multiple output voltages output by the high-voltage power supply module, and to generate a detection signal corresponding to each output voltage; The signal processing module is connected to the abnormality detection module and the main control module respectively. The signal processing module is used to send a positioning signal to the main control module when the detection signal corresponding to at least one output voltage indicates that the output voltage is abnormal. The positioning signal is used to indicate that there is an abnormal output voltage among the multiple output voltages.

2. The abnormality detection circuit according to claim 1, characterized in that: The signal processing module includes: a processing unit and an analog-to-digital conversion unit; One end of the processing unit is connected to the abnormality detection module, and the other end of the processing unit is connected to the analog-to-digital conversion unit; The processing unit is used to generate a first signal after processing at least one abnormal signal; the abnormal signal is a detection signal indicating that the output voltage is abnormal; The analog-to-digital conversion unit is used to convert the first signal into the positioning signal, wherein the positioning signal includes a duty cycle characteristic.

3. The abnormality detection circuit according to claim 1, characterized in that: The signal processing module comprises: a processing unit and a limiting unit, one end of the processing unit is connected to the abnormality detection module, and the other end of the processing unit is connected to the limiting unit; The processing unit is used to generate a first signal after processing at least one abnormal signal; the abnormal signal is a detection signal indicating that the output voltage is abnormal; The limiting unit is used to limit the first signal to generate the positioning signal, wherein the positioning signal includes a voltage value feature.

4. The abnormality detection circuit according to claim 2 or 3, characterized in that: The processing unit comprises: a plurality of voltage dividing subunits and an operation subunit, wherein a first end of the voltage dividing subunit is connected to the abnormality detection module, a second end of the voltage dividing subunit is connected to a first input end of the operation subunit, and a second input end of the operation subunit is grounded; The voltage dividing subunit is used to generate a corresponding reference voltage according to the abnormal signal; and the operation subunit is used to accumulate the reference voltages to generate the first signal.

5. The abnormality detection circuit according to claim 2, characterized in that: The abnormality detection circuit also includes an interface unit, which is used to connect with the main control module and output the positioning signal to the main control module.

6. The abnormality detection circuit according to claim 2, characterized in that: The analog-to-digital conversion unit is a pulse width modulation unit, and the pulse width modulation unit includes a comparator and a triangular wave generator; The first input terminal of the comparator is connected to the output terminal of the processing unit, and the second input terminal of the comparator is connected to the triangular wave generator; The triangular wave generator is used to generate a triangular wave signal; The comparator is used to synthesize the first signal and the triangular wave signal into the positioning signal.

7. The abnormality detection circuit according to claim 3, characterized in that: The abnormality detection circuit also includes an interface unit, which has an ADC function and is used to connect to the main control module and output the positioning signal to the main control module.

8. The abnormality detection circuit according to claim 1, characterized in that: The abnormality detection module includes a plurality of abnormality detection units, and the abnormality detection units are connected to the high-voltage power supply module; The abnormality detection unit is used to output a high-level detection signal when detecting that the output voltage is abnormal; When it is detected that the output voltage is normal, a low level detection signal is output.

9. The abnormality detection circuit according to claim 3, characterized in that: The amplitude limiting unit includes a voltage-stabilizing diode and a capacitor. The first end of the voltage-stabilizing diode is connected to the processing unit, the second end of the voltage-stabilizing diode is grounded, and the capacitor is connected in parallel with the voltage-stabilizing diode.

10. A high voltage board, characterized in that: It comprises the abnormality detection circuit and high-voltage power supply module as described in any one of claims 1 to 9.

11. The high voltage board according to claim 10, characterized in that: The high-voltage power supply module includes a plurality of high-voltage generating units, and the output end of the high-voltage generating unit is connected to the abnormality detection module for generating an output voltage and outputting the output voltage to the abnormality detection module.

12. An imaging device, characterized in that: It comprises the high voltage board according to any one of claims 10 or 11 and a main control module connected thereto; The main control module is used to determine whether an abnormal high-voltage generating unit exists on the high-voltage board according to a positioning signal output by the high-voltage board.

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