Control circuit for manual handle of endoscope

Abstract

The utility model relates to a manual handle control circuit of an endoscope, and belongs to the technical field of electronic control and signal processing. The circuit adopts a modular design and comprises a power supply module, a control module, an input and output module, a light control module, a USB interface module and a current detection module. The power supply module provides stable voltage through the booster circuit and supports normal operation of other functional modules; the control module takes a microcontroller as a core and realizes brightness adjustment and mode switching of the LED lamp through a PWM (Pulse-Width Modulation) signal; the input and output module provides GPIO and IIC interfaces to prepare for adding zoom. The USB interface module supports communication with external equipment; and the current detection module monitors the driving current of the LED lamp in real time to ensure safe operation. The circuit is compact in structure and suitable for the intelligent manual endoscope. Compared with the prior art, the system has the advantages of being high in integration level, multifunctional, low in power consumption and the like, is suitable for being applied to working scenes of industrial endoscopes, and has wide popularization value.

Description

TECHNICAL FIELD

[0001] The utility model relates to a manual handle control circuit of endoscope belongs to electronic control and signal processing field, especially applicable to the manual device with multifunctional light control and communication interface. BACKGROUND

[0002] Industrial endoscopes are usually used to inspect the internal conditions of equipment or pipelines, such as in the fields of industrial inspection, maintenance and detection. In order to clearly observe the inspected object in a complex environment, the endoscope needs a stable and bright enough light source. Since LEDs have the advantages of high brightness, low power consumption and long service life, they are often used as the light source of endoscopes.

[0003] The existing manual handle usually has simple functions, such as basic on-off control and single light effect. However, in some application scenarios, the manual handle needs to support complex signal processing, multiple light modes and communication capabilities with external devices. However, in the traditional design to realize these functions, the circuit is complex and bulky, which is difficult to meet the requirements of handheld devices on integration and reliability. SUMMARY

[0004] The utility model aims at providing a manual handle control circuit with simple design and high integration, which can realize multiple light control modes, current monitoring function and communication capabilities with external devices.

[0005] In order to solve the above technical problems, the utility model is realized by the following technical schemes:

[0006] The circuit includes a power module for providing a stable power supply voltage, including inductance L1, filter capacitor C3, C4 and rectifier diode D1;

[0007] The control module contains microcontroller U3 and its connected crystal oscillator U6, which is used for signal processing and control function;

[0008] The input and output module contains signal receiving and sending port USART2RX, USART2TX and PWM signal output port LED_PWM for light control;

[0009] The USB interface module includes first USB port U9 and second USB port U10, which realizes communication with external devices;

[0010] The light control module includes LED lamp LED+, triode Q1, Q2, Q3 and related resistance network R1, R2, R3, which controls light brightness and switching through PWM signal;

[0011] Current detection module, INA139U4 and precision resistance are used to realize current sampling, which is used for real-time monitoring of light driving current.

[0012] Further, the power module further comprises a boost circuit U1 for boosting the input voltage to the operating voltage required for driving the LED.

[0013] Further, the control module further comprises a plurality of GPIO interfaces for connecting an external key switch J2 to realize manual function selection.

[0014] Further, the external switch connected by the GPIO interface further comprises a light switching function for controlling different working modes of the LED through the light switching signal.

[0015] Further, the light control module is provided with an operational amplifier U2A, an operational amplifier U2B and an operational amplifier U4.

[0016] The non-inverting input end of the operational amplifier U2A is connected to the signal input end in series with the resistor R1 and the resistor R2, and is grounded through the capacitor C1 and the capacitor C2.

[0017] The inverting input end of the operational amplifier U2A is connected to the output end of the operational amplifier U2A through the feedback resistor R8 and the compensation capacitor C6, and is grounded through the current limiting resistor R5.

[0018] The output end of the operational amplifier U2A is connected to the base of the transistor, and is connected to the inverting input end through the feedback resistor R8 and the compensation capacitor C6.

[0019] Further, the non-inverting input end of the operational amplifier U2B is connected to the power supply VCC_LED through the resistor R9.

[0020] The inverting input end of the operational amplifier U2B is grounded through the resistor R13.

[0021] The output end of the operational amplifier U2B is grounded through the resistor R11, and is connected to the voltage signal node LED_CHANG through the current limiting resistor R12.

[0022] Further, the transistor is composed of a transistor Q1, a transistor Q2 and a transistor Q3; the base of the transistor Q1 is connected to the output end of the operational amplifier U2A, and is connected to the inverting input end of the operational amplifier U2 through the feedback resistor R8; the emitter of the transistor Q1 is connected to the base of the transistor Q2; the collector of the transistor Q2 is connected to the base of the transistor Q3; the collector of the transistor Q3 is connected to the power supply VCC_LED, and is connected to the LED+ through the load.

[0023] The beneficial effects are:

[0024] The utility model discloses a modular design, power module, control module, input and output module, light control module, current detection module and other function definite partition, circuit structure is clear, convenient debugging and maintenance. Meanwhile, the high integration of circuit reduces the volume and cost, makes it suitable for the demand of handheld endoscope.

[0025] The utility model discloses a plurality of mode switching of LED lamp is realized through PWM signal and switch signal, including brightness adjustment and light mode change. User can satisfy individualized demand through manual or remote control, enhances the intelligent and applicability of equipment.

[0026] Through the integration USART and IIC interface, prepare for the follow-up increase zoom control. BRIEF DESCRIPTION OF DRAWINGS

[0027] For easy to explain, the utility model discloses the detailed description of the following specific implementation and drawing.

[0028] Figure 1 For the circuit diagram of the utility model

[0029] Figure 2 For the light module circuit diagram of the utility model;

[0030] Figure 3 For the power management circuit diagram of the utility model;

[0031] Figure 4 For the circuit diagram of linear voltage regulator of the utility model;

[0032] Figure 5 For the circuit diagram of UBS concentrator of the utility model;

[0033] Figure 6 For the circuit diagram of integrated chip of the utility model;

[0034] Figure 7 For the circuit diagram of UBS plug-in terminal of the utility model. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the utility model in detail, and the examples of the embodiments are shown in the drawings. The embodiments described below by referring to the drawings are exemplary, and are intended to explain the utility model, and cannot be understood as the limitation of the utility model.

[0036] Reference Figures 1-7 For a kind of embodiment of the utility model one endoscope manual handle control circuit,

[0037] Specific working steps include:

[0038] The power module works as follows: the input voltage is boosted to 5V or above by the boost circuit U1 to power the light module and other functional modules. The current is further smoothed by inductor L1 and filter capacitors C3, C4, and rectifier diode D1 is used to prevent reverse current.

[0039] The signal processing of the control module: the microcontroller U3 receives signals from the switch J2, such as light switching and brightness adjustment instructions. The microcontroller outputs a dimming signal LED_PWM through the PWM interface, and exchanges data with external devices through the IIC interface.

[0040] The brightness control of the light module: the light module uses the PWM signal to adjust the brightness of the LED lamp LED+, and the transistors Q1, Q2, Q3 amplify the control signal to ensure the normal operation of the LED lamp. The current detection module U4 monitors the light current and provides a feedback signal to protect the circuit.

[0041] The communication function of the USB interface module: the USB interfaces U9, U10 realize data communication through the USB signal port of the microcontroller. The first interface is used to connect external PCs, and the second interface is used to connect other devices such as storage devices.

[0042] In this circuit, the second-order RC filter circuit is set at the signal input end and is composed of resistors R1, R2, R5, capacitors C1, and C2. One end of resistor R1 is connected to the signal input end, and the other end is connected to resistor R2 and capacitor C2. One end of resistor R2 is connected to capacitor C1. The second-order RC filter circuit is mainly to make the input current more stable.

[0043] The operational amplifier circuit includes operational amplifiers U2A, U2B, and U4. The non-inverting input end (pin 3) of operational amplifier U2A is connected to the signal input end in series with resistors R1 and R2, and is grounded through capacitors C1 and C2.

[0044] Function: receives the input signal (the voltage of LED_EN) as the main control signal of the operational amplifier, compares it with the feedback signal, and determines the output.

[0045] The inverting input end (pin 2) of operational amplifier U2A is connected to the output end (pin 1) of operational amplifier U2A through feedback resistor R8 and compensation capacitor C6, and is grounded through current-limiting resistor R5.

[0046] Function: receives the feedback signal to compare the voltage difference between the non-inverting input signal (pin 3) and the feedback signal, adjusts the output, and stabilizes the gain of the operational amplifier through negative feedback and limits the output fluctuation.

[0047] The output end (pin 1) of operational amplifier U2A is connected to the base of the transistor, and is connected to the inverting input end (pin 2) through feedback resistor R8 and compensation capacitor C6.

[0048] The effect of this setting is that the output voltage of the op amp controls the base current of transistor Q1, thereby driving the subsequent transistors Q2 and Q3, and ultimately controlling the on and off of the LED.

[0049] Pin 4 of the op amp U2A is grounded, and pin 8 is connected to the power supply VCC_LED, which provides operating voltage for the entire op amp to support its normal amplification function.

[0050] The non-inverting input terminal (pin 5) of the op amp U2B is connected to the power supply VCC_LED through the resistor R9;

[0051] The main function is to provide a reference voltage signal, which is provided by R9 and the power supply VCC_LED, for comparison with the inverting input signal (pin 6).

[0052] The inverting input of op amp U2B (pin 6) is grounded through resistor R13; its function is to receive the negative input signal, compare the voltage difference with the positive input (pin 5), and control the output of the op amp (pin 7).

[0053] The output of op amp U2B (pin 7) is connected to ground through resistor R11 and to the voltage signal node LED_CHANG through current limiting resistor R12;

[0054] Function: As the output terminal of the op amp, it outputs the result signal to control the circuit status. LED_CHANG can be used as a status indicator or feedback signal to other circuit modules.

[0055] Pin 4 of op amp U2B is grounded, and pin 8 is connected to the power supply VCC_LED to provide operating voltage for the entire op amp to support its normal amplification function.

[0056] The main function of op amp U2B is to transmit the output result to the LED_CHANG node through R11 and R12 at the output end (pin 7) for status indication or further control of the changing behavior of the LED.

[0057] The U4INA139 in this system is a dedicated current sensing amplifier. It detects the voltage difference between IN+ and IN− as current flows through the amplifier and amplifies this voltage difference to the output terminal OUT for subsequent circuit processing. Its main function is current monitoring: ensuring that the operating current of the LED or driver does not exceed the designed value.

[0058] Overcurrent protection: If the detected current exceeds a threshold, a protection mechanism (such as disconnecting the drive circuit) can be triggered through a signal.

[0059] Circuit regulation: Dynamically adjust the working state of the LED (such as brightness or on / off control) according to the current value.

[0060] Feedback Regulation: R8 and operational amplifier U2A form a negative feedback loop, stabilizing the output and preventing overdrive caused by excessive current.

[0061] The triodes in this system are composed of triode Q1, triode Q2, and triode Q3. The base of triode Q1 is connected to the output of operational amplifier U2A and simultaneously connected to the inverting input of operational amplifier U2 through feedback resistor R8. The emitter of triode Q1 is connected to the base of triode Q2.

[0062] Role of Triode Q1:

[0063] Signal Amplification: The signal output by operational amplifier U2A is connected to the base of triode Q1, which amplifies and drives the current. The amplified current is output through the emitter, driving the next stage of triode Q2.

[0064] Driving Subsequent Stages: The emitter current of triode Q1 controls the conduction state of triode Q2 (and subsequently triode Q3), ultimately determining whether the current at the LED+ terminal passes through, controlling the on-off state of the LED.

[0065] The collector of triode Q2 is connected to the base of triode Q3.

[0066] Role of Triode Q2:

[0067] Driving Intermediate Stages: The main role of triode Q2 is to act as an intermediate amplifier, receiving signals from triode Q1 and further amplifying them to drive triode Q3. It serves as an amplifier while providing sufficient base current for the subsequent triode Q3.

[0068] Current Control: The base current of triode Q2 (provided by triode Q1) controls the current flow at its collector. By controlling the conduction of triode Q2, the current size and on-off state of the subsequent stages (triode Q3 and LED) can be indirectly controlled.

[0069] Cascade Control: Triodes Q1 and Q2 amplify the output signal of operational amplifier U2A in a cascading manner to provide sufficient current to drive the LED. This design reduces the burden on individual triodes, improving driving capacity and stability.

[0070] The collector of triode Q3 is connected to the power supply VCC_LED and simultaneously connected to the LED+ through the load.

[0071] Role of Triode Q3:

[0072] Final Power Amplification: Triode Q3 is the final driving device in the circuit, receiving signals from triode Q2 and controlling the current path between the collector and emitter through the base current. It can handle larger currents and directly drive the LED.

[0073] Switch control: whether the triode Q3 is on or not determines whether the load (LED) is lit. If the base has no driving signal, the triode Q3 is not conductive, and the LED has no current flowing through it, in the off state; when the triode Q3 is conductive, the LED starts to work.

[0074] Protection and stability: capacitors C7 and C27 play a filtering role to avoid high-frequency interference in the power supply or base input signal affecting the circuit work. This design increases the stability of the circuit.

[0075] The integrated chip is connected with power management circuit, linear voltage regulator, two UBS hubs on the power;

[0076] The power management circuit in the system uses LT1930 chip; it is a DC-DC converter, which is used to raise the lower input voltage to a higher output voltage;

[0077] The model of linear voltage regulator is SP6205ADJ; it is a low dropout voltage regulator, which can work stably when the voltage difference between input voltage and output voltage is small. In other words, it can work when the input voltage is slightly higher than the output voltage, and it is suitable for battery-powered or low-voltage difference circuits.

[0078] The USB hub in the present application is an expansion device that can expand one USB port into multiple ports, allowing multiple USB devices to be connected through one host port.

[0079] At the same time, the main function of the UBS hub combined with the crystal oscillator is to ensure that the data transmission between USB devices is carried out under accurate timing. The crystal oscillator provides a stable clock signal for the hub, thereby ensuring the stability, timeliness and reliability of USB communication.

[0080] The above is only a specific embodiment of the present application, but the technical features of the present application are not limited to this, any person skilled in the art in the field of the present application, the change or modification is covered in the patent range of the present application.

Claims

1. An endoscope manual handle control circuit, characterized in that: The circuit includes: a power supply module for providing a stable power supply voltage, including an inductor L1, filter capacitors C3, C4 and a rectifier diode D1; a control module, including a microcontroller U3 and a crystal oscillator U6 connected thereto, for implementing signal processing and control functions; an input and output module, including signal receiving and transmitting ports USART2RX and USART2TX and a PWM signal output port LED_PWM for light control; a USB interface module, including a first USB port U9 and a second USB port U10, for implementing communication with external devices; a light control module, including an LED lamp LED+, transistors Q1, Q2, Q3 and resistors R1, R2, R3 in series with the non-inverting input terminal, for controlling light brightness and switching through PWM signals; a current detection module, using INA139U4 and precision resistors to implement current sampling, for real-time monitoring of the light drive current.

2. The endoscope manual handle control circuit according to claim 1, characterized in that: The power module further includes a boost circuit U1 for boosting the input voltage to an operating voltage required to drive the LED.

3. The endoscope manual handle control circuit according to claim 2, characterized in that: The control module also includes a plurality of GPIO interfaces for connecting to an external key switch J2 to implement manual function selection.

4. The endoscope manual handle control circuit according to claim 3, characterized in that: The external switch connected to the GPIO interface also includes a light switching function, which is used to control different working modes of the LED through light switching signals.

5. The endoscope manual handle control circuit according to claim 4, characterized in that: The lighting control module is provided with an operational amplifier U2A, an operational amplifier U2B, and an operational amplifier U4; the non-inverting input terminal of the operational amplifier U2A is connected to the signal input terminal via series resistors R1 and R2, and is grounded via capacitors C1 and C2; the inverting input terminal of the operational amplifier U2A is connected to the output terminal of the operational amplifier U2A via a feedback resistor R8 and a compensation capacitor C6, and is grounded via a current-limiting resistor R5; the output terminal of the operational amplifier U2A is connected to the base of the transistor, and is connected to the inverting input terminal via the feedback resistor R8 and the compensation capacitor C6.

6. The endoscope manual handle control circuit according to claim 5, characterized in that: The non-inverting input of the operational amplifier U2B is connected to the power supply VCC_LED through a resistor R9; the inverting input of the operational amplifier U2B is grounded through a resistor R13; the output of the operational amplifier U2B is grounded through a resistor R11 and connected to the voltage signal node LED_CHANG through a current limiting resistor R12.

7. The endoscope manual handle control circuit according to claim 5, characterized in that: The transistors are composed of a transistor Q1, a transistor Q2, and a transistor Q3; the base of the transistor Q1 is connected to the output of the operational amplifier U2A, and is connected to the inverting input of the operational amplifier U2 through the feedback resistor R8; the emitter of the transistor Q1 is connected to the base of the transistor Q2; the collector of the transistor Q2 is connected to the base of the transistor Q3; the collector of the transistor Q3 is connected to the power supply VCC_LED, and is connected to LED+ through a load.

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