A smart door lock's on / off status icon LCD display module

Abstract

This utility model discloses a smart door lock's open / closed status icon LCD display module, including a control board and an LCD screen connected to the control board. The LCD screen is a cholesteric liquid crystal bistable display. The control board integrates an MCU microcontroller, a boost circuit, and a display drive circuit. The boost circuit and display drive circuit are connected to the MCU microcontroller circuit. The MCU microcontroller outputs a PWM signal to the boost circuit, which provides the voltage required by the display drive circuit. The display drive circuit is connected to the cholesteric liquid crystal bistable display and drives the cholesteric liquid crystal bistable display to display the unlock icon or the closed icon. Due to the bistable characteristics of cholesteric liquid crystal, the displayed icon status can remain stable in the absence of power, realizing a smart door lock display screen with continuous display of unlock or closed status icons, maintaining low power consumption, and the display of unlock or closed status icons does not affect the smart door lock's battery life.

Description

Technical Field

[0001] This disclosure relates to the field of smart door lock technology, and in particular to a liquid crystal display module for displaying the lock status icons of a smart door lock. Background Technology

[0002] A door lock is a locking device installed on a door to prevent unauthorized entry. Existing door locks include mechanical locks opened with a mechanical key and electronic smart locks opened with a password, fingerprint, or mechanical key. Electronic smart locks typically unlock by entering a password or fingerprint, avoiding the inconvenience of carrying a mechanical key. However, electronic smart locks retain the mechanical key unlocking function to prevent the circuitry from failing to activate the motor and extend the bolt when the battery is low. Existing electronic smart locks, considering standby power consumption, display LEDs momentarily when the lock is open or closed (e.g., green for open, red for closed). However, the LEDs turn off immediately after unlocking or closing, making it impossible to determine the lock status in standby mode. If the indicator lights or icons displayed for extended periods in standby mode, it would significantly increase battery consumption, impacting the smart lock's battery life. Utility Model Content

[0003] To overcome the shortcomings of the existing technology, this utility model proposes a liquid crystal display module for the lock status icons of a smart door lock. This liquid crystal display module can display the lock status icons with low power consumption in the standby state of the smart lock.

[0004] The technical solution of this utility model is a smart door lock's open / closed status icon LCD display module, including a control board and an LCD screen connected to the control board. The LCD screen is a cholesteric bistable liquid crystal display. The control board integrates an MCU microcontroller, a boost circuit, and a display drive circuit. The boost circuit and the display drive circuit are connected to the MCU microcontroller circuit. The MCU microcontroller outputs a PWM signal to the boost circuit. The boost circuit is used to provide the voltage required by the display drive circuit. The display drive circuit is connected to the cholesteric bistable liquid crystal display and is used to drive the cholesteric bistable liquid crystal display to display an unlock icon or a close icon.

[0005] Furthermore, the cholesteric liquid crystal bistable display screen employs three independent cholesteric liquid crystal layers of red, green, and blue stacked vertically.

[0006] Furthermore, the display screen driving circuit includes 3 COM terminal circuits and 15 SEG terminal circuits. The 3 COM terminal circuits respectively control and activate the red, green, and blue independent cholesteric liquid crystal layers of the cholesteric liquid crystal bistable display screen. The 15 SEG terminal circuits are divided into three groups of 5, each corresponding to control and illuminate the red, green, and blue independent cholesteric liquid crystal layers of the cholesteric liquid crystal bistable display screen.

[0007] Furthermore, the boost circuit includes a VCC terminal, a diode D40, a capacitor C16, an NPN transistor Q85, a P-channel MOSFET Q86, an N-channel MOSFET Q87, resistors R214, R215, R216, and R217, and an inductor L3. The VCC terminal, after rectification by diode D40, is connected to capacitor C16. The other end of C16 is connected to the emitter of the NPN transistor Q85 and ground. The base of the NPN transistor Q85 is connected to the output PWM signal terminal of the MCU microcontroller. The collector of the NPN transistor Q85 is connected to inductor L3. The other end of inductor L3 is connected to the gate of the N-channel MOSFET Q87. The drain of N-channel MOSFET Q87 is connected to the gate of P-channel MOSFET Q86. The source of P-channel MOSFET Q86 is connected to the MCU microcontroller. The source of N-channel MOSFET Q87 is connected to the output PWM signal terminal of the MCU microcontroller through resistor R214. Resistor R215 is connected between the source and gate of N-channel MOSFET Q87. Resistor R215 is connected to resistor R216. The other end of resistor R216 is connected to the HV_EN terminal of the MCU microcontroller. Resistor R217 is connected between the source and gate of P-channel MOSFET Q86. The source of P-channel MOSFET Q86 is connected to the VBAT terminal of the MCU microcontroller. The VCC terminal is connected to the display screen driver circuit.

[0008] Furthermore, the COM terminal circuit includes a P-channel MOSFET Q88, an N-channel MOSFET Q89, an NPN transistor Q90, resistors R218, R219, R220, R221, R222, R223, and R224, diodes D41 and D42. The source of the P-channel MOSFET Q88 is connected to the VCC terminal via resistor R222. Resistors R220, R221, and R222 are connected in series and connected to the drain of the N-channel MOSFET Q89. The gate of the P-channel MOSFET Q88 is connected between resistors R220 and R221. The source of the P-channel MOSFET Q88... The source and drain of the N-channel MOSFET Q89 are connected to diode D41. Resistor R219 is connected to the source of the N-channel MOSFET Q89. The other end of resistor R219 is connected to the gate of the N-channel MOSFET Q89. Resistor R218 is connected to the gate of the N-channel MOSFET Q89. The other end of resistor R218 is connected to the COM_H terminal. The COM_H terminal is connected to the MCU microcontroller. The base of the NPN transistor Q90 is connected to the COM_L terminal via resistor R223. The COM_L terminal is connected to the MCU microcontroller. Diode D42 is connected between the emitter and collector of the NPN transistor Q90. Resistor R224 is connected between the emitter and base of the NPN transistor Q90.

[0009] Furthermore, the SEG terminal circuit and the COM terminal circuit have the same structure. In the SEG terminal circuit, the COM_L terminal in the corresponding COM terminal circuit is the SEG_L terminal, and the COM_H terminal is the SEG_H terminal. The SEG_L terminal and the SEG_H terminal are connected to the MCU microcontroller.

[0010] Furthermore, the MCU microcontroller uses an MCU chip with the model number HC32L136K8TA-LQFP64.

[0011] This solution designs a smart lock's on / off status icon LCD display module. When applied to a smart lock, it enables the smart lock to feature a cholesteric liquid crystal bistable display. When the internal motor drives the bolt to extend or retract, it triggers the MCU microcontroller to activate the boost circuit, along with 3 COM channels and 15 SEG channels, to work together to illuminate and switch the unlocked and locked status icons on the display. Due to the bistable nature of cholesteric liquid crystals, the displayed icon status remains stable even without power until the MCU microcontroller sends a new signal to change the voltage, thus switching the display between unlocked and locked status icons. This achieves a smart lock display with continuously displayed unlocked or locked status icons, maintaining low power consumption, and ensuring that the display of unlocked or locked status icons does not affect the smart lock's battery life. Attached Figure Description

[0012] Figure 1This is a block diagram of the LCD display module for the on / off status icons of the smart door lock of this utility model.

[0013] Figure 2 The circuit structure diagram of the HC32L136K8TA-LQFP64 MCU microcontroller used in this utility model is shown.

[0014] Figure 3 This is a schematic diagram of the boost circuit structure of this utility model.

[0015] Figure 4 This is a circuit diagram of the COM terminal of this utility model.

[0016] Figure 5 This is a circuit diagram of the SEG terminal of this utility model.

[0017] Figure 6 This is a schematic diagram of the cholesteric phase liquid crystal bistable display screen of this utility model.

[0018] Figure 7 This is a schematic diagram of the unlock icon status displayed on the cholesteric liquid crystal bistable display screen of this utility model.

[0019] Figure 8 This is a schematic diagram of the cholesteric liquid crystal bistable display screen of this utility model showing the lock icon status. Detailed Implementation

[0020] The technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this disclosure.

[0021] Please refer to Figures 1 to 6 This invention discloses a smart door lock's on / off status icon LCD display module, comprising a control board and an LCD screen connected to the control board. The LCD screen is a cholesteric bistable liquid crystal display (CPI). The control board integrates an MCU microcontroller, a boost circuit, and a display driver circuit. The boost circuit and display driver circuit are connected to the MCU microcontroller. The MCU microcontroller outputs a PWM signal to the boost circuit, which provides the voltage required by the display driver circuit. The display driver circuit is connected to the CPI bistable liquid crystal display and drives it to display the unlock or lock icon. The MCU microcontroller uses an HC32L136K8TA-LQFP64 chip, and the control board is connected to the LCD screen via an FPC flexible cable.

[0022] Furthermore, the cholesteric liquid crystal bistable display screen employs three vertically stacked independent cholesteric liquid crystal layers: red, green, and blue. The display screen driving circuit includes 3 COM terminal circuits and 15 SEG terminal circuits. The 3 COM terminal circuits respectively control and activate the three independent cholesteric liquid crystal layers (red, green, and blue) of the cholesteric liquid crystal bistable display screen. The 15 SEG terminal circuits are divided into three groups of 5, each corresponding to and controlling the illumination of the three independent cholesteric liquid crystal layers (red, green, and blue) of the cholesteric liquid crystal bistable display screen.

[0023] Specifically, the boost circuit includes a VCC terminal, diode D40, capacitor C16, NPN transistor Q85, P-channel MOSFET Q86, N-channel MOSFET Q87, resistors R214, R215, R216, R217, and inductor L3. The VCC terminal, after rectification by diode D40, is connected to capacitor C16. The other end of C16 is connected to the emitter of NPN transistor Q85 and ground. The base of NPN transistor Q85 is connected to the output PWM signal terminal of the MCU microcontroller. The collector of NPN transistor Q85 is connected to inductor L3. The other end of inductor L3 is connected to the gate of N-channel MOSFET Q87. The drain of N-channel MOSFET Q87 is connected to the gate of P-channel MOSFET Q86. The source of P-channel MOSFET Q86 is connected to the MCU microcontroller. The source of N-channel MOSFET Q87 is connected to the output PWM signal terminal of the MCU microcontroller through resistor R214. Resistor R215 is connected between the source and gate of N-channel MOSFET Q87. Resistor R215 is connected to resistor R216. The other end of resistor R216 is connected to the HV_EN terminal of the MCU microcontroller. Resistor R217 is connected between the source and gate of P-channel MOSFET Q86. The source of P-channel MOSFET Q86 is connected to the VBAT terminal of the MCU microcontroller. The VCC terminal is connected to the display screen driver circuit.

[0024] Specifically, the COM terminal circuit includes a P-channel MOSFET Q88, an N-channel MOSFET Q89, an NPN transistor Q90, resistors R218, R219, R220, R221, R222, R223, and R224, diodes D41 and D42. The source of the P-channel MOSFET Q88 is connected to the VCC terminal via resistor R222. Resistors R220, R221, and R222 are connected in series and connected to the drain of the N-channel MOSFET Q89. The gate of the P-channel MOSFET Q88 is connected between resistors R220 and R221. The source of the P-channel MOSFET Q88... The source of the N-channel MOSFET Q89 is connected to the drain of diode D41, and the other end of resistor R219 is connected to the gate of the N-channel MOSFET Q89. The gate of the N-channel MOSFET Q89 is connected to resistor R218, and the other end of resistor R218 is connected to the COM_H terminal. The COM_H terminal is connected to the MCU microcontroller. The base of the NPN transistor Q90 is connected to the COM_L terminal via resistor R223. The COM_L terminal is connected to the MCU microcontroller. Diode D42 is connected between the emitter and collector of the NPN transistor Q90, and resistor R224 is connected between the emitter and base of the NPN transistor Q90.

[0025] Reference Figure 1 , Figure 4 , Figure 5 The SEG terminal circuit and the COM terminal circuit have the same structure. In the SEG terminal circuit, the COM_L terminal in the corresponding COM terminal circuit is the SEG_L terminal, and the COM_H terminal is the SEG_H terminal. The SEG_L terminal and the SEG_H terminal are connected to the MCU microcontroller. The MCU controller has 3 COM_L terminal and COM_H terminal pins and 15 SEG_L terminal and SEG_H terminal pins.

[0026] Reference Figure 7 , Figure 8 The cholesteric liquid crystal bistable display uses three independent cholesteric liquid crystal layers: red, green, and blue. Figure 7 Taking the display of a white unlock icon against a black background as an example, the implementation process is as follows: Three COM circuits simultaneously activate the SEG electrodes in the icon area, causing all three icon areas to enter a planar state. The SEG electrodes in the background area are deactivated, and all three layers are in a focal conic state. The three color layers mix light to display the white unlock icon, while the background area, in its focal conic state, absorbs all ambient light and appears black. Figure 8Taking a black lock icon against a red background as an example, the implementation process is as follows: The COM circuit activates the SEG electrode of the red layer, causing the red layer to enter a planar state in the background area and reflect red light; the SEG electrode in the icon area is turned off, and all three layers are in a focal conical state, absorbing light and displaying a black icon; the COM circuit of the green / blue layers is completely turned off, maintaining a focal conical state. The cholesteric liquid crystal bistable display switches between icon displays by outputting +40V / -40V pulses through PWM control.

[0027] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A smart door lock's on / off status icon LCD display module, comprising a control board and an LCD screen connected to the control board, characterized in that, The liquid crystal display screen is a cholesteric liquid crystal bistable display screen. The control board integrates an MCU microcontroller, a boost circuit, and a display screen driver circuit. The boost circuit and the display screen driver circuit are connected to the MCU microcontroller circuit. The MCU microcontroller outputs a PWM signal to the boost circuit. The boost circuit is used to provide the voltage required by the display screen driver circuit. The display screen driver circuit is connected to the cholesteric liquid crystal bistable display screen and is used to drive the cholesteric liquid crystal bistable display screen to display an unlock icon or a lock icon.

2. The smart door lock's on / off status icon LCD display module according to claim 1, characterized in that, The cholesteric liquid crystal bistable display screen uses three independent cholesteric liquid crystal layers of red, green and blue stacked vertically.

3. The smart door lock's on / off status icon LCD display module according to claim 2, characterized in that, The display screen driving circuit includes 3 COM terminal circuits and 15 SEG terminal circuits. The 3 COM terminal circuits control and activate the red, green and blue independent cholesteric liquid crystal layers of the cholesteric liquid crystal bistable display screen respectively. The 15 SEG terminal circuits are divided into three groups of 5, each group corresponding to control and illuminate the red, green and blue independent cholesteric liquid crystal layers of the cholesteric liquid crystal bistable display screen respectively.

4. The smart door lock's on / off status icon LCD display module according to claim 3, characterized in that, The boost circuit includes a VCC terminal, diode D40, capacitor C16, NPN transistor Q85, P-channel MOSFET Q86, N-channel MOSFET Q87, resistors R214, R215, R216, and R217, and inductor L3. The VCC terminal, after rectification by diode D40, is connected to capacitor C16. The other end of C16 is connected to the emitter of NPN transistor Q85 and ground. The base of NPN transistor Q85 is connected to the output PWM signal terminal of the MCU microcontroller. The collector of NPN transistor Q85 is connected to inductor L3. The other end of inductor L3 is connected to the gate of N-channel MOSFET Q87. The drain of the N-channel MOSFET Q87 is connected to the gate of the P-channel MOSFET Q86. The source of the P-channel MOSFET Q86 is connected to the MCU microcontroller. The source of the N-channel MOSFET Q87 is connected to the output PWM signal terminal of the MCU microcontroller through resistor R214. Resistor R215 is connected between the source and gate of the N-channel MOSFET Q87. Resistor R215 is connected to resistor R216. The other end of resistor R216 is connected to the HV_EN terminal of the MCU microcontroller. Resistor R217 is connected between the source and gate of the P-channel MOSFET Q86. The source of the P-channel MOSFET Q86 is connected to the VBAT terminal of the MCU microcontroller. The VCC terminal is connected to the display screen driver circuit.

5. The smart door lock's on / off status icon LCD display module according to claim 4, characterized in that, The COM terminal circuit includes a P-channel MOSFET Q88, an N-channel MOSFET Q89, an NPN transistor Q90, resistors R218, R219, R220, R221, R222, R223, and R224, diodes D41 and D42. The source of the P-channel MOSFET Q88 is connected to the VCC terminal via resistor R222. Resistors R220, R221, and R222 are connected in series and connected to the drain of the N-channel MOSFET Q89. The gate of the P-channel MOSFET Q88 is connected between resistors R220 and R221. The source and drain of the P-channel MOSFET Q88 are connected... The source of the N-channel MOSFET Q89 is connected to the diode D41, and the other end of the resistor R219 is connected to the gate of the N-channel MOSFET Q89. The gate of the N-channel MOSFET Q89 is connected to the resistor R218, and the other end of the resistor R218 is connected to the COM_H terminal. The COM_H terminal is connected to the MCU microcontroller. The base of the NPN transistor Q90 is connected to the COM_L terminal via the resistor R223. The COM_L terminal is connected to the MCU microcontroller. The emitter and collector of the NPN transistor Q90 are connected to the diode D42, and the emitter and base of the NPN transistor Q90 are connected to the resistor R224.

6. The smart door lock's on / off status icon LCD display module according to claim 5, characterized in that, The SEG terminal circuit and the COM terminal circuit have the same structure. In the SEG terminal circuit, the COM_L terminal in the corresponding COM terminal circuit is the SEG_L terminal, and the COM_H terminal is the SEG_H terminal. The SEG_L terminal and the SEG_H terminal are connected to the MCU microcontroller.

7. The smart door lock's on / off status icon LCD display module according to any one of claims 1-6, characterized in that, The MCU microcontroller uses an HC32L136K8TA-LQFP64 MCU chip.

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