Headlight ear trimmer

Abstract

The application discloses a head light emitting ear hair cutter, and relates to the technical field of ear canal care auxiliary appliances, which comprises a driving motor, a movable inner cutter, a fixed protective cover, an illuminating part, a touch pressure detection part, a motor load detection part and a circuit control board. The fixed protective cover is located outside the movable inner cutter and forms a hair entering gap, and a fixed shearing edge is formed at the edge of the hair entering gap; the movable inner cutter moves inside the fixed protective cover and cooperates with the ear hair cutting. The illuminating part emits light towards the front of the fixed protective cover and the hair entering area. The touch pressure detection part and the motor load detection part respectively acquire pressing information and cutting load information; the circuit control board forms a protection pressing risk result and a cutting blockage risk result based on the two, forms a stable trimming, tightening buffer, unloading recovery or safety locking control request based on the combination relationship of the two, and controls the illuminating part and the driving motor based on the control request. The application takes into account ear hair shearing, local illumination, skin isolation and abnormal protection.

Description

Technical Field

[0001] This invention relates to the field of ear canal care aids, and more specifically, to a head-illuminated ear hair trimmer. Background Technology

[0002] Ear hair trimmers are mainly used for trimming hair at the entrance of the ear canal or in the shallow part of the external ear canal. The working part at the front end needs to be operated in a small space with insufficient light and sensitive skin, while taking into account the lighting of the trimming area and the isolation of the ear canal skin.

[0003] In the prior art, CN104224441B discloses a visual ear pick, which relates to an ear canal cleaning device that uses lighting and cameras to assist users in observing the inside of the ear canal and cleaning earwax.

[0004] The solution includes a rod-shaped ear pick body, a camera unit with a light source, an ear pick located at the front end of the ear pick body and capable of being inserted into the ear canal, and a rotating part for rotating the ear pick; the camera unit is used to capture images inside the ear canal and transmit the images to an external device, and the user adjusts the direction of the ear pick and cleans according to the display screen.

[0005] However, in ear hair trimming scenarios, the front working part also needs to be isolated from the ear canal skin by a fixed protective cover, allowing the ear hair to enter the cutting area formed by the movable inner blade and the fixed cutting edge through the hair entry gap. The above solution does not provide corresponding detection, lighting, and motor linkage control for situations where the fixed protective cover is not installed properly, the fixed protective cover is pressed against the ear canal skin, or the movable inner blade experiences abnormal load due to ear hair or earwax.

[0006] Therefore, it is still necessary to provide a head-illuminated ear hair cutter to illuminate the area in front of the fixed protective cover and the hair-feeding area, and to implement linkage control of the lighting element and drive motor based on the fixed protective cover's position status, pressure information, and cutting load information of the movable inner blade. Summary of the Invention

[0007] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a head-illuminated ear hair trimmer, which forms a safe cutting structure by means of a fixed protective cover and a movable inner blade, and implements linkage control of the lighting component and the drive motor based on the pressure information of the fixed protective cover and the cutting load information of the movable inner blade, so as to solve the problem that existing ear canal care devices are difficult to simultaneously take into account the lighting of the trimming area, the isolation of the ear canal skin, and the control of pressure and obstruction risks.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A head-illuminated ear hair trimmer includes a housing, a blade holder, a drive motor, a transmission shaft, a movable inner blade, a fixed protective cover, an illumination element, a pressure detection element, a motor load detection element, and a circuit control board. The drive motor drives the movable inner blade to move relative to the fixed protective cover via the transmission shaft. The fixed protective cover is disposed outside the movable inner blade and forms a hair-feeding gap. The edge of the hair-feeding gap forms a fixed shearing edge that engages with the movable inner blade for shearing. The illumination element emits light towards the front of the fixed protective cover and the area corresponding to the hair-feeding gap. The pressure detection element is used to detect pressure on the fixed protective cover. Based on the information, the motor load detection device is used to obtain the cutting load information of the movable inner blade; the circuit control board is used to form a protection pressure risk result and a cutting resistance risk result respectively based on the pressure information and the cutting load information in the same control cycle, determine the cutting resistance judgment boundary of the current control cycle based on the protection pressure risk result of the previous control cycle, determine the protection pressure judgment boundary of the current control cycle based on the cutting resistance risk result of the previous control cycle, and control the lighting device and the drive motor according to the combination relationship between the protection pressure risk result and the cutting resistance risk result of the current control cycle.

[0010] In a preferred embodiment, the device further includes a fixed protective sleeve and a blade mounting position. The blade mounting position is located at the front end of the blade holder. The fixed protective sleeve is installed at the blade mounting position and fixedly connected to the blade holder. The fixed protective cover is installed at the front end of the fixed protective sleeve. The fixed protective cover does not rotate circumferentially relative to the blade holder and the fixed protective sleeve. The root of the fixed protective cover undergoes radial or axial elastic displacement under the limiting fit between the fixed protective sleeve and the fixed protective cover. The limiting fit restricts the elastic displacement, so that the areas on the fixed protective cover other than the area forming a shearing fit relationship remain spaced from the movable inner blade.

[0011] In a preferred embodiment, the fixed protective cover includes a fixed outer blade portion, and the fixed protective sleeve includes a light-transmitting portion. The fixed outer blade portion is made of metal material, and the hair infeed gap and the fixed shearing edge are formed on the fixed outer blade portion. The cutting edge of the movable inner blade forms a close-fitting shearing relationship or a gap shearing relationship with the fixed shearing edge. In the close-fitting shearing relationship, the movable inner blade has an elastic blade arm or an elastic cutting portion, and the cutting edge is close to the inner side of the fixed shearing edge by the elastic deformation of the elastic blade arm or the elastic cutting portion. In the gap shearing relationship, the cutting edge of the movable inner blade maintains a gap with the fixed shearing edge that is determined according to the ear hair diameter, the radial runout of the movable inner blade, the inner diameter of the fixed protective cover, the coaxiality of the drive shaft, and the assembly tolerance.

[0012] In a preferred embodiment, the illuminator is fixed to a portion of the fixed protective sleeve, the blade mounting position, or the fixed protective cover that does not rotate with the drive shaft. The light emission direction of the illuminator is towards the hair inlet gap and its corresponding cutting area. A light emission gap is formed between the illuminator and the light-transmitting part. The illuminator is connected to the circuit control board via a flexible wire. The flexible wire is arranged along the area of ​​the fixed protective sleeve or the blade bar that does not rotate with the drive shaft and is spaced apart from the movement path of the drive shaft and the movable inner blade.

[0013] In a preferred embodiment, the pressure detection element includes a conductive contact and an elastic conductive sheet. The root of the fixed protective cover is provided with a pressure-bearing and force-transmitting portion, which forms a circumferentially extending pressure-bearing annular surface. The pressure-bearing annular surface is disposed opposite to the elastic conductive sheet. When the fixed protective cover is subjected to radial pressure, the pressure-bearing and force-transmitting portion undergoes radial displacement along with the root of the fixed protective cover corresponding to the pressure position, and pushes the elastic conductive sheet to deform. When the fixed protective cover is subjected to axial pressure, the pressure-bearing and force-transmitting portion undergoes axial displacement, and pushes the elastic conductive sheet to press against the conductive contact. A dirt-blocking and sealing structure is provided on the outer side of the contact area between the conductive contact and the elastic conductive sheet.

[0014] In a preferred embodiment, the circuit control board detects the equivalent contact resistance between the conductive contact and the elastic conductive sheet via a contact resistance sampling branch; when the fixed protective cover is not installed in place, the equivalent contact resistance is within the "not in place" judgment range; when the fixed protective cover is installed in place and not under pressure, the equivalent contact resistance is within the "in place" judgment range; when the fixed protective cover is subjected to pressure that further presses the elastic conductive sheet against the conductive contact, the equivalent contact resistance is within the "touch pressure" judgment range; the "not in place" judgment range, the "in place" judgment range, and the... The pressure detection ranges do not overlap, and isolation zones are set between adjacent detection ranges. The circuit control board forms a normalized pressure value based on the ratio of the difference between the contact resistance reference when the fixed protective cover is installed in place and not under pressure and the current equivalent contact resistance, relative to the difference between the contact resistance reference and the pressure reference resistance. The circuit control board forms a pressure state based on the normalized pressure value, including an in-place, unpressurized state, a pressure risk increase state, an effective pressure state, and a continuous pressure state. When the normalized pressure value is lower than the first pressure entry boundary... The system is configured to: form an in-place, unpressurized state; when the normalized pressure value reaches the first pressure entry boundary but is below the second pressure entry boundary, and continues to reach the first confirmation time, a pressure risk increase state is formed; when the first confirmation time has not yet been reached, the in-place, unpressurized state is maintained; when the normalized pressure value reaches the second pressure entry boundary but the duration has not reached the second confirmation time, an effective pressure state is formed; when the normalized pressure value reaches the second pressure entry boundary and continues to reach the second confirmation time, a sustained pressure state is formed; when in the sustained pressure state, the normalized pressure value drops below the second pressure exit boundary and continues to reach the recovery confirmation time, then it is reduced to the effective pressure state; when in the effective pressure state or the pressure risk increase state, the normalized pressure value drops below the first pressure exit boundary and continues to reach the recovery confirmation time, then it is reduced to the in-place, unpressurized state; when the recovery confirmation time has not yet been reached, the current pressure state is maintained, the first pressure exit boundary is lower than the first pressure entry boundary, and the second pressure exit boundary is lower than the second pressure entry boundary.

[0015] In a preferred embodiment, the motor load detection device includes a motor current sampling branch for collecting the operating current of the drive motor, and the circuit control board is further connected to a lighting current detection branch for collecting the operating current of the lighting element. When the fixed protective cover is in position, the pressure state is the in-position, non-pressured state, the current supply voltage is within the operating voltage range, and the operating current of the lighting element is within the lighting current judgment range, the circuit control board controls the drive motor to enter a low-speed testing state. In the low-speed testing state, the circuit control board shields the start-up surge of the drive motor and, based on the average operating current and operating current continuously collected after the surge shielding ends... The fluctuation amount determines the installation status of the active blade; when the average operating current exceeds the blade installation current range, or the fluctuation amount of the operating current exceeds the blade installation fluctuation range, an abnormal blade installation state is formed and the establishment of an unloaded reference is prohibited; when the installation status of the active blade is normal, and the fluctuation amount of the operating current does not exceed the unloaded reference establishment boundary and continues to reach the reference confirmation time, the unloaded reference is established based on the continuously collected operating current; the low-speed test allowable time is the total allowable time from entering the low-speed test state to forming a valid unloaded reference, and the low-speed test allowable time is based on the surge shielding start time, the active blade installation status judgment time, and the reference. The definite confirmation time is determined; the circuit control board determines the dynamic stall reference current based on the stall reference current calibrated under the reference supply voltage and the current supply voltage, and forms a normalized load value based on the ratio of the difference between the current operating current and the no-load reference to the difference between the dynamic stall reference current and the no-load reference; the circuit control board forms a load state based on the normalized load value, the load duration, and the load recovery time; when the normalized load value is lower than the first load entry boundary, a normal cutting state is formed; when the normalized load value reaches the first load entry boundary and drops below the first load exit boundary within the normal recovery time, the normal cutting state is maintained. When the load value fails to drop below the first load exit boundary after the normal recovery time has elapsed, a slow load recovery state is formed. When the normalized load value reaches the second load entry boundary and continues to reach the blockage confirmation time, a blockage trend state is formed. When the blockage confirmation time has not yet been reached, the slow load recovery state is formed or maintained. When the normalized load value reaches the stall entry boundary and continues to reach the stall confirmation time, or when the drive circuit of the drive motor triggers hardware overcurrent protection, a stall state is formed. The first load exit boundary is the load recovery boundary and is lower than the first load entry boundary, and the second load entry boundary is higher than the first load entry boundary and lower than the stall entry boundary.

[0016] In a preferred embodiment, the circuit control board includes a protection pressure risk module and a cutting resistance risk module. The protection pressure risk module is used to form a boundary hold, boundary tightening, or safety lock as the result of the protection pressure risk based on the fixed protective cover's in-position status, the normalized pressure value, the pressure duration, the number of pressure jitters, the pressure release recovery time, the sampling validity flag, and the pressure fault code. The cutting resistance risk module is used to form a boundary hold, boundary tightening, unloading recovery, or safety lock as the result of the cutting resistance risk based on the normalized load value, the no-load reference, the load duration, the load recovery time, the number of repeated load events, the reference validity flag, and the load fault code. In the low-speed probing state and when the no-load reference has not yet been established, the cutting resistance risk module forms a reference establishment in progress flag, does not calculate the normalized load value, and does not form the cutting resistance risk result. The protection pressure risk module continues to generate the protection pressure risk result; after the no-load reference is established and the reference validity flag is valid, the reference establishment flag is cleared, and the protection pressure risk module and the cutting resistance risk module generate their respective risk results in parallel within the same control cycle based on the data associated with the same control cycle; at the beginning of each control cycle, the circuit control board determines the effective boundary group of the cutting resistance risk module in the current control cycle based on the protection pressure risk result of the previous control cycle, and determines the effective boundary group of the protection pressure risk module in the current control cycle based on the cutting resistance risk result of the previous control cycle; when the dual-risk parallel analysis result is generated for the first time, the protection pressure risk module and the cutting resistance risk module adopt the factory-set basic boundary group; the modulation result of the effective boundary group is maintained for at least one complete control cycle and is limited to the boundary minimum and boundary maximum values ​​specified in the parameter package.

[0017] In a preferred embodiment, the circuit control board generates control requests based on the combination of the protection pressure risk result and the cutting stall risk result. These control requests include a stability trimming request, a tightening buffer request, an unloading recovery request, and a safety lock request. When the baseline establishment flag is valid, the stability trimming request is not generated, and the circuit control board maintains the low-speed probing state. The stability trimming request is generated when both the protection pressure risk result and the cutting stall risk result are boundary holdable. The tightening buffer request is generated when the protection pressure risk result is boundary tightening and the cutting stall risk result is boundary holdable, or when the protection pressure risk result is boundary holdable and the cutting stall risk result is boundary tightening. The unloading recovery request is generated when the protection pressure risk result is boundary holdable and the cutting stall risk result is unloading recovery. The unloading recovery request is generated when the protection pressure risk result is boundary tightening and the cutting stall risk result is either boundary tightening or unloading recovery. When the following occurs, a safety lockout request is generated; a safety lockout request is generated when any of the following situations occur: the protection pressure risk result is a safety lockout; the cutting jamming risk result is a safety lockout; the sampling validity flag of the protection pressure risk module is invalid; after the no-load reference is established, the reference validity flag of the cutting jamming risk module changes from valid to invalid; the low-speed test state exceeds the allowed low-speed test time and still has not formed a valid no-load reference; the protection pressure risk module fails to generate the protection pressure risk result within the output time limit determined by the control cycle; when the flag is invalid during the reference establishment, the cutting jamming risk module fails to generate the cutting jamming risk result within the output time limit determined by the control cycle; or the fault code of any module is valid; when multiple control requests are valid at the same time, the circuit control board executes the control request with higher protection priority in the order of the safety lockout request, the unloading recovery request, the tightening buffer request, and the stabilization trimming request.

[0018] In a preferred embodiment, the circuit control board controls the lighting element and the drive motor through a low-level state machine. The control states of the low-level state machine include an off state, a low-brightness preparation state, a low-speed probing state, a stable trimming state, a tightening buffer state, an unloading recovery state, and a safety lock state, and these control states are mutually exclusive. In the off state, the lighting element and the drive motor are off. In the low-brightness preparation state, the lighting element is at low brightness and the drive motor is off. In the low-speed probing state, the drive motor operates according to the probing drive duty cycle. In the stable trimming state, the lighting element is constantly on and the drive motor operates according to the stable trimming drive duty cycle. In the tightening buffer state, the lighting element is at high brightness and the drive motor operates at a drive duty cycle lower than the stable trimming drive duty cycle. In the unloading recovery state, the drive motor is off, and the lighting element outputs a flashing unloading or cleaning prompt. In the safety lock state, the drive motor remains off and is prohibited from starting. When the operating current of the lighting element is within the lighting current judgment range, the lighting element outputs a fault prompt. When exiting the tightening buffer state... When the normalized pressure value drops below the first pressure exit boundary and continues to reach the recovery confirmation time, the pressure state is restored to the in-position unpressurized state. After the normalized load value drops below the load recovery boundary and continues to reach the load recovery confirmation time, the underlying state machine returns to the low-speed probing state. In the unloading recovery state, when the circuit control board receives a user's reset operation and detects that the fixed protective cover is in the in-position state, the pressure state is the in-position unpressurized state, and the static output of the motor load detection device is within the normal range of the shutdown state, the underlying state machine returns to the low-speed probing state. When the tightening buffer state or the unloading recovery state fails to meet the exit conditions within their respective allowed durations, the underlying state machine enters the safety lock state. In the safety lock state, after all fault flags causing the safety lock have been cleared and the circuit control board receives a user's reset operation, the underlying state machine sequentially performs fixed protective cover in-position verification, lighting self-test, pressure reference confirmation, low-speed probing, and no-load reference confirmation. Only after all the above checks are passed is it allowed to enter the stable trimming state.

[0019] The technical effects and advantages of the luminous ear hair trimmer of this invention:

[0020] This invention forms an inner and outer blade cutting structure by using a fixed protective cover and a movable inner blade. This allows ear hair to enter through the hair entry gap and be cut between the fixed cutting edge and the movable inner blade. The movable inner blade is located inside the fixed protective cover, thereby reducing the risk of the ear canal skin directly contacting the movable inner blade while achieving ear hair trimming.

[0021] The lighting element is positioned on the non-moving part of the blade head, emitting light towards the front of the fixed protective cover and the area where the hair enters, which helps improve observation conditions at the ear canal entrance or in the shallow part of the external ear canal. The pressure detection element and the motor load detection element respectively acquire information on the pressure of the fixed protective cover and the cutting load of the moving inner blade. The circuit control board controls the lighting indicators and drive the motor operation based on the combination of these two types of risk results, allowing for differentiated handling of normal trimming, pressure risk, slow load recovery, entanglement, and stall.

[0022] This invention also employs control processes such as low-speed probing, no-load benchmark establishment, cross-control cycle boundary modulation, tightening buffer, unloading recovery, and safety locking to classify and handle issues such as abnormal blade installation, inadequate protective cover placement, single risk increase, and simultaneous increase in pressure and load. The risk outcome of the previous control cycle is used to modulate the judgment boundary of another risk in the current control cycle, allowing both types of risks to be judged in parallel within the current control cycle without forming a circular dependency. Re-execution of in-situ verification and no-load benchmark confirmation after the anomaly is resolved improves the safety and control stability of the ear hair trimming process. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a head-illuminated ear hair trimmer according to the present invention.

[0024] Figure 2 This is a partial cross-sectional view of the front end of the cutter head of the present invention.

[0025] Figure 3 This is a block diagram of the control structure of the circuit control board of the present invention.

[0026] Figure 4 This is a schematic diagram of the dual-risk parallel analysis and underlying state machine of the present invention.

[0027] Figure 5 This is a timing diagram for load changes, lighting prompts, and motor control in this invention.

[0028] Figure 6 This is a flowchart of the detection and calibration process of the present invention.

[0029] 100. Head-lit ear hair trimmer; 110. Housing; 120. Internal mounting area; 130. Switch; 140. Power supply assembly; 150. Circuit control board; 160. Drive motor; 170. Drive shaft; 200. Blade holder; 210. Blade head mounting position; 220. Ear insertion depth limiting part; 300. Movable inner blade; 310. Cutting serration part; 400. Fixed protective cover; 410. Fixed protective cover root; 420. Dirt-blocking sealing structure; 430. Fixed outer blade part; 440. Hair entry gap; 450. Fixed cutting edge; 460. Pressure-bearing and force-transmitting part; 500. Fixed protective sleeve; 510. Light-transmitting part; 520. Light-emitting gap; 600. Illumination component; 700. Touch pressure detection component; 710. Conductive contact; 720. Elastic conductive sheet; 800. Motor load detection component. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] Example 1, as Figure 1 As shown, this embodiment provides a head-illuminated ear hair trimmer 100, including a housing 110, a blade 200, a drive shaft 170, a movable inner blade 300, a fixed protective sleeve 500, a fixed protective cover 400, an illumination element 600, a touch pressure detection element 700, a motor load detection element 800, a circuit control board 150, a drive motor 160, a power supply assembly 140, and a switch 130.

[0032] The power supply assembly 140, circuit control board 150, and drive motor 160 are mounted within the internal mounting area 120 formed by the housing 110. A switch 130 is connected to the circuit control board 150 and is used to start, stop, and reset the ear hair trimmer. The drive motor 160 drives the movable inner blade 300 via a drive shaft 170 arranged along the blade holder 200. The circuit control board 150 includes a motor drive circuit, a lighting drive circuit, a lighting current detection branch, a motor current sampling branch, and a storage unit. The motor drive circuit has a drive enable terminal and a hardware overcurrent protection terminal.

[0033] The front end of the blade holder 200 is provided with a blade head mounting position 210. A fixed protective sleeve 500 is fixed to the blade head mounting position 210, and a fixed protective cover 400 is installed at the front end of the fixed protective sleeve 500. During the trimming process, the fixed protective cover 400 does not rotate circumferentially relative to the blade holder 200, and its root 410 can generate radial or axial elastic displacement under the limiting fit. The elastic displacement is limited by the limiting structure between the fixed protective cover 400 and the fixed protective sleeve 500, so that the area of ​​the fixed protective cover 400 other than the designed shearing area is kept at a distance from the movable inner blade 300.

[0034] The movable inner blade 300 is detachably connected to the front end of the drive shaft 170. The two can use a flat, spline, or polygonal mating fit to transmit torque, and the movable inner blade 300 is prevented from disengaging by a snap-fit ​​structure or an axial limiting structure.

[0035] like Figure 2 As shown, the movable inner blade 300 is located inside the fixed protective cover 400, and its outer periphery is provided with a cutting serration 310. The fixed protective cover 400 includes a fixed outer blade portion 430, which forms a hair infeed gap 440. The hair infeed gap 440 forms a fixed shearing edge 450 near the edge of the movable inner blade 300. After the ear hair passes through the hair infeed gap 440, it is cut between the fixed shearing edge 450 and the cutting edge of the movable inner blade 300. The movable inner blade 300 does not extend outward from the hair infeed gap 440 in its normal operating position.

[0036] The movable inner blade 300 and the fixed shearing edge 450 can form a close-fitting shearing relationship or a gap shearing relationship. When using a close-fitting shearing relationship, the movable inner blade 300 generates pre-pressure through an elastic blade arm or elastic cutting section; the pre-pressure is determined based on simulated hair cutting, no-load current, continuous operating temperature rise, and wear tests, and can be selected within the range of 0.02 N to 0.20 N. When using a gap shearing relationship, the gap is determined based on the ear hair diameter, the radial runout of the movable inner blade 300, the inner diameter of the fixed protective cover 400, the coaxiality of the drive shaft 170, and assembly tolerances.

[0037] The opening size of the hair insertion gap 440 is determined based on the simulated ear hair insertion test and the silicone ear canal model pressing test, and can be selected within the range of 0.15 mm to 0.50 mm. After the fixed protective cover 400 is compressed, the ear canal model must not enter the movement area of ​​the movable inner blade 300, the movable inner blade 300 must not extend outward, and continuous friction must not be formed outside the designed shearing area.

[0038] The fixed protective cover 500 includes a light-transmitting part 510, and a light-emitting gap 520 is formed between the illuminator 600 and the light-transmitting part 510. The outer side of the fixed protective cover 400 may also be provided with an ear insertion depth limiting part 220, the outer diameter of which is larger than the outer diameter of the working section of the fixed protective cover 400, to limit the depth of the blade entering the ear canal.

[0039] Example 2 illustrates an optional structure for the fixed protective cover 400.

[0040] The fixed protective cover 400 can adopt a metal hollow structure, a metal mesh structure, or a spring-like structure. In the metal hollow structure, the strip grooves, holes, or circumferential openings form a brush inlet gap 440, and the inner edge of the opening forms a fixed shearing edge 450; in the metal mesh structure, the edges of each mesh hole form a fixed shearing edge 450.

[0041] When a spring-like structure is used, an ear-like entry gap is formed between adjacent spring coils. The root of the spring-like structure is fixed to the fixed protective sleeve 500 and restricts circumferential rotation. A fixed shearing ring or a fixed outer blade 430 is provided on its inner side. When the spring coil is directly used as the fixed shearing edge 450, its radial stiffness, wire diameter, coil spacing, and root fixing strength should be determined through a compression deformation test.

[0042] The outer surface of the fixed protective cover 400 is rounded, polished, or passivated. Factory inspections include appearance, dimensions, insertion and removal, indentation, simulated hair cutting, and ear canal model pressure tests. The fixed protective cover 400 is deemed to have failed when it undergoes irreversible deformation, continuous contact outside the designed shearing area, abnormal increase in pre-pressure in the designed shearing area, or extension of the movable inner blade 300.

[0043] Example 3, as Figure 2 As shown, the illuminator 600 is fixed to the fixed protective sleeve 500, the cutter head mounting position 210, or the fixed protective cover 400 at a location that does not rotate with the drive shaft 170, and its light emission direction is towards the bristle inlet gap 440 and the corresponding shearing area. The light-transmitting part 510 can be a flat window, an arc-shaped window, or a partial light-transmitting area, and a light emission gap 520 is maintained between the illuminator 600 and the light-transmitting part 510.

[0044] The lighting element 600 is connected to the circuit control board 150 via a flexible wire. The flexible wire is arranged along the non-rotating area of ​​the fixed protective sleeve 500 or the tool bar 200 and is spaced apart from the movement path of the drive shaft 170 and the movable inner blade 300.

[0045] The lighting output includes off, low brightness, constant brightness, high brightness, and flashing. The lighting driver module determines the brightness level, drive duty cycle, and flashing code based on the switch status, supply voltage, current control status, lighting current detection value, and fault code.

[0046] When the lighting current is below the open circuit judgment lower limit, the lighting component 600 is determined to be open circuit; when it is above the overcurrent judgment upper limit or the hardware overcurrent protection is activated, the lighting drive is determined to be short circuit or overcurrent. In the event of a lighting fault, the circuit control board 150 shuts down the drive motor 160 and generates a safety lockout request. The lighting self-test is performed before the low-speed test; if the self-test fails to produce a valid result within the self-test time, a safety lockout is initiated. The self-test time is determined based on the response time of the lighting drive circuit and can be selected within the range of 100 milliseconds to 500 milliseconds.

[0047] Example 4 illustrates the in-situ detection and pressure detection of the fixed protective cover 400.

[0048] The base 410 of the fixed protective cover is provided with a pressure-bearing and force-transmitting part 460, which forms a circumferentially extending pressure-bearing ring surface. The pressure detection element 700 includes a conductive contact 710 and an elastic conductive sheet 720, with the pressure-bearing ring surface and the elastic conductive sheet 720 disposed opposite to each other.

[0049] When the fixed protective cover 400 is subjected to radial pressure, the pressure-bearing and force-transmitting part 460 generates radial displacement and pushes the elastic conductive sheet 720 to deform; when subjected to axial pressure, the pressure-bearing and force-transmitting part 460 generates axial displacement and pushes the elastic conductive sheet 720 to further press the conductive contact 710. The pressure-bearing and force-transmitting part 460 can convert pressure in different directions into displacement toward the elastic conductive sheet 720 by tilting the force-transmitting surface, or it can cooperate with multiple elastic conductive sheets 720 arranged at intervals along the circumference. The elastic displacement of the root 410 of the fixed protective cover can be selected in the range of 0.02 mm to 0.20 mm.

[0050] The circuit control board 150 detects the equivalent contact resistance between the conductive contact 710 and the elastic conductive sheet 720 through the contact resistance sampling branch. When the fixed protective cover 400 is not installed properly, installed properly but not under pressure, or under pressure, the equivalent contact resistance falls within the non-in-position judgment range, the in-position judgment range, and the contact pressure judgment range, respectively. These three ranges do not overlap, and an isolation zone is provided between adjacent ranges. If the sampled value remains within the isolation zone for an extended period, a contact pressure detection anomaly is output.

[0051] To minimize the impact of contact material, oxidation, temperature, and assembly tolerances, the contact pressure condition can be determined using a normalized contact pressure value. The normalized contact pressure value is preferably determined according to the following formula:

[0052] ;

[0053] in: This represents the normalized pressure value; This indicates the contact resistance reference when the fixed protective cover 400 is installed in place and not under pressure. This represents the equivalent contact resistance obtained from the current sampling. This represents the contact reference resistance obtained during factory calibration with a specified contact load.

[0054] when Not greater than ,or and When the difference between the two values ​​is less than the minimum effective difference that the contact resistance sampling branch can stably identify, the circuit control board 150 determines that the contact pressure calibration has failed, does not perform the normalized contact value calculation, and outputs the contact pressure calibration abnormality status.

[0055] A set of possible state boundaries is as follows:

[0056] when When the pressure level is below the first pressure entry boundary, the output shows the position without pressure.

[0057] when When the first pressure entry boundary is reached but below the second pressure entry boundary, and continues to reach the first confirmation time, the pressure risk increases.

[0058] when When the second pressure entry boundary is reached but the duration does not reach the second confirmation time, the valid pressure state is output.

[0059] when When the second pressing boundary is reached and the second confirmation time is reached, the continuous pressing state is output.

[0060] when The pressure level can only be reduced after the pressure drops below the corresponding exit boundary and remains below the recovery confirmation time. The first pressure exit boundary is lower than the first pressure entry boundary, and the second pressure exit boundary is lower than the second pressure entry boundary, to create a state hysteresis.

[0061] The first confirmation time, the second confirmation time, and the recovery confirmation time are determined based on the contact sampling cycle, the elastic recovery time of the fixed protective cover (400°), and the silicone ear canal model pressure test.

[0062] For example, the first pressure entry boundary can be selected between 0.2 and 0.4, and the second pressure entry boundary can be selected between 0.5 and 0.7. Different values ​​are used for the entry and exit boundaries to form hysteresis, in order to avoid frequent state jumps.

[0063] The sampling period of the pressure detection module can be selected from 5 milliseconds to 20 milliseconds. The confirmation time for the fixed protective cover 400 to be in position can be selected from 50 milliseconds to 200 milliseconds; the confirmation time for the loss of the position signal can be shorter than the confirmation time, for example, it can be selected from 20 milliseconds to 100 milliseconds.

[0064] The touch pressure detection module outputs a status frame. The status frame includes at least a status code, the current contact resistance value or normalized contact value, a validity flag, a fault code, a parameter version number, and a timestamp.

[0065] The pressure detection status includes not in position, in position but not under pressure, increased risk of pressure contact, effective pressure contact, continuous pressure contact, and detection abnormality.

[0066] When there is an open circuit in the contact resistance, an abnormal short circuit, the sampling range is exceeded, the signal remains unchanged for a long time, the number of jitters exceeds the allowable number, or the device is in a continuous pressure state when it is powered on, the output will detect an abnormal state.

[0067] A dirt-blocking sealing structure 420 is provided on the outer side of the contact area between the conductive contact 710 and the elastic conductive sheet 720 to reduce the entry of earwax, grease, and moisture into the contact area. The dirt-blocking sealing structure 420 shall not impede the effective movement of the elastic conductive sheet 720.

[0068] Example 5 illustrates motor load detection.

[0069] The motor load detection device 800 collects the operating current of the drive motor 160 through the motor current sampling branch. When using the load feedback signal from the drive chip, it is first converted into an equivalent load value based on its calibration relationship with the controlled stalled load.

[0070] When entering the low-speed testing state, the circuit control board 150 sets the reference establishment flag to active and shields the start-up surge of the drive motor 160. The surge shielding time is determined based on the decay process of the start-up current and can be selected within the range of 100 milliseconds to 300 milliseconds.

[0071] After the surge shielding is completed, when the fixed protective cover 400 is in place, the pressure state is in place and not under pressure, the power supply voltage is within the working voltage range, and the lighting current is within the lighting current judgment range, the circuit control board 150 judges the installation status of the movable inner blade 300 based on the continuously collected average working current and the working current fluctuation.

[0072] If the average operating current exceeds the blade installation current range, or if the operating current fluctuation exceeds the blade installation fluctuation range, an abnormal blade installation status is output, and the establishment of an unloaded reference is prohibited. If the blade 300 is installed normally during the activity period, and the operating current fluctuation does not exceed the unloaded reference establishment boundary and continues to reach the reference confirmation time, an unloaded reference I0 is established based on continuous sampling values. The reference validity flag is set to valid, and the reference establishment in progress flag is cleared. During the period when the reference establishment in progress flag is valid, normalized load values ​​are not calculated, and the cutting resistance risk module does not participate in the formation of stable trimming requests.

[0073] The allowed low-speed test time is the total allowable time from entering the low-speed test state to the formation of a valid no-load reference, determined based on the surge shielding activation time, the determination time of the active blade installation status, and the reference confirmation time. If a valid no-load reference is not formed after the allowed low-speed test time, the circuit control board 150 clears the reference establishment in progress flag, outputs a no-load reference establishment failure fault code, and a safety lockout request.

[0074] The dynamic stall reference current is preferably determined according to the following formula:

[0075] ;

[0076] in: This represents the dynamic stall reference current under the current power supply voltage conditions; This represents the stall reference current calibrated under the reference power supply voltage; This indicates the currently detected power supply voltage; This indicates the reference power supply voltage used during stall calibration. When the value is zero, missing, or exceeds the effective calibration range, the circuit control board 150 determines that the load calibration is abnormal and does not perform dynamic stall reference current calculation.

[0077] The above dynamic stall reference current calculation applies to situations where the drive output is not subject to hardware current limiting, the drive duty cycle remains at the corresponding calibration conditions, and the stall current is approximately proportional to the power supply voltage. When the drive circuit has constant current, segmented current limiting, or nonlinear modulation characteristics, a stall reference current lookup table is established based on controlled stall tests under different power supply voltages and drive duty cycles, and the dynamic stall reference current is determined by the current power supply voltage and drive duty cycle.

[0078] When the power supply voltage is lower than the operating lower limit or the drive circuit has triggered hardware current limiting, the above dynamic stall reference current calculation is not performed, and the corresponding abnormal state or safety lock-up request is directly output.

[0079] The normalized load value is determined according to the following formula:

[0080] ;

[0081] in: This represents the normalized load value; This represents the current operating current of the motor after filtering. This represents the no-load reference current formed during the low-speed testing phase. This indicates the dynamic stall reference current.

[0082] when Not greater than ,or and When the difference between the values ​​is not greater than the minimum effective difference that the current sampling circuit can stably identify, the circuit control board 150 determines that the load calibration is abnormal and does not perform the normalized load value calculation. If the value is less than 0, treat it as 0. If the value is greater than 1, it will be treated as 1. It can also be converted to a percentage value output from 0% to 100%.

[0083] During normal cutting, the load value increases briefly and then falls back within a specified recovery time; when the load recovery is slow, the load value remains above the first load entry boundary for a certain period of time, but does not reach the stall entry boundary; when there is a stalling trend, the load value continues to rise or fails to fall back within the recovery time multiple times; when stalled, the normalized load value reaches the stall entry boundary and continues to reach the stall confirmation time, or the drive circuit triggers hardware overcurrent protection.

[0084] A typical set of boundary conditions that can be adopted is as follows:

[0085] when When the load is less than the first load threshold, output the normal load status.

[0086] when When the load reaches the first load entry boundary but is below the second load entry boundary, and falls back below the first load exit boundary within the normal recovery time, the normal cutting state is still output; if the load does not fall back below the first load exit boundary after the normal recovery time, the slow load recovery state is output.

[0087] when When the load reaches the second load entry boundary but is below the stall entry boundary, and the duration does not reach the stall confirmation time, maintain the slow load recovery state; when the stall confirmation time is reached, output the stall trend state.

[0088] when When the stall condition reaches the entry boundary and continues to be confirmed for a period of time, or when the drive circuit triggers hardware overcurrent protection, the stall condition is output.

[0089] For example, the first load entry boundary can be selected in the range of 0.30 to 0.40, the second load entry boundary can be selected in the range of 0.55 to 0.65, and the stall entry boundary can be selected in the range of 0.80 to 0.90. The above boundaries and confirmation times are calibrated by simulated hair density test, earwax simulant retardation test, and controlled stall test.

[0090] The load recovery time boundary is determined based on the current drop-off curve after the hair leaves the cutting zone. For example, the normal recovery time can be selected within the range of 100 milliseconds to 500 milliseconds. Different calibration values ​​can be used for different motors, blade structures, and speeds.

[0091] The motor load detection module outputs a status frame. The status frame includes at least the normalized load value, load duration, load recovery time, current status code, baseline validity flag, fault code, parameter version number, and timestamp.

[0092] Load status includes normal cutting, slow load recovery, entanglement tendency, stalled rotor, and abnormal load detection.

[0093] When the drive motor 160 is turned off, if a continuous high current is detected, the sampled value remains unchanged for a long time, the no-load reference exceeds the historical range, the no-load reference fluctuates too much, or the sampling branch exceeds the range, the output load detection is in an abnormal state.

[0094] If the no-load reference is significantly higher than the factory range, there may be friction between the inner and outer blades, blade eccentricity, or contamination. If the no-load reference is significantly lower than the factory range, there may be that the moving inner blade 300 is not installed, the transmission is disengaged, or the load detection branch is malfunctioning. Stable trimming is prohibited in any of these situations.

[0095] Example 6, as Figure 3 and Figure 4 As shown, this embodiment illustrates dual-risk parallel analysis, cross-cycle boundary modulation, and joint control requests. Figure 4 The dual-risk parallel analysis relationship shown applies to the control phase after the no-load baseline has been established and the baseline validity flag is valid. During the validity period of the flag during baseline establishment, the protection pressure risk module continues to operate, the cutting stall risk module does not generate a cutting stall risk result, and the circuit control board remains in a low-speed probing state. The baseline establishment process is performed according to Example 5. The protection pressure effective boundary and the cutting stall effective boundary represent the effective boundary groups used by the corresponding risk modules, respectively. The effective boundary groups include entry boundaries, exit boundaries, duration boundaries, and recovery time boundaries.

[0096] The inputs to the protection pressure risk module include the fixed protective cover in place status, normalized pressure value, pressure duration, pressure jitter count, pressure release recovery time, sampling validity flag, and pressure fault code. Its risk results include boundary retention, boundary tightening, and safety locking.

[0097] The inputs to the cutting stall risk module include normalized load value, no-load reference, load duration, load recovery time, number of repeated load events, reference establishment in progress flag, reference valid flag, and load fault code. Its risk results include boundary hold, boundary tightening, unload recovery, and safety lock.

[0098] When the baseline establishment flag is valid, the cutting stall risk module does not generate cutting stall risk results and does not participate in the formation of stable trimming requests; the protection pressure risk module continues to operate. After the no-load baseline is valid, the two risk modules generate the risk results for this cycle in parallel based on the data associated with the same control cycle.

[0099] The number of touch-pressure jitters is counted based on the confirmed round-trip transitions of the touch-pressure state; instantaneous changes before the state confirmation time is reached are not counted. A repetitive load event refers to a situation where the normalized load value reaches the first load entry boundary and then drops below the load recovery boundary within the load recovery time; a new event is only counted when the previous event has recovered and the interval between the two events reaches the minimum event interval. When the number of touch-pressure jitters reaches the touch-pressure tightening boundary, the protection pressure risk module generates a boundary tightening result; when it reaches the touch-pressure abnormality boundary, a safety lockout result is generated. When the number of repetitive load events reaches the load tightening boundary, the cutting blockage risk module generates a boundary tightening result; when it reaches the load abnormality boundary, an unloading recovery result is generated.

[0100] At the beginning of each control cycle, the circuit control board 150 determines the effective boundary group of the cutting resistance risk module for the current control cycle based on the protection pressure risk result of the previous control cycle, and determines the effective boundary group of the protection pressure risk module for the current control cycle based on the cutting resistance risk result of the previous control cycle.

[0101] When the first parallel analysis results of dual risks are generated, there are no risk results from the previous control cycle. The protection pressure risk module and the cutting resistance risk module adopt the factory basic boundary group. Thereafter, each control cycle modulates the effective boundary group of the current control cycle according to the risk results of the previous control cycle.

[0102] The parameter package stores the protection pressure base boundary group, the protection pressure tightening boundary group, the cutting inhibition base boundary group, and the cutting inhibition tightening boundary group, respectively. If the protection pressure risk result of the previous control cycle is boundary maintenance, the cutting inhibition risk module of the current control cycle uses the cutting inhibition base boundary group; if the protection pressure risk result of the previous control cycle is boundary tightening, the cutting inhibition risk module of the current control cycle uses the cutting inhibition tightening boundary group. The first load entry boundary and the second load entry boundary in the cutting inhibition tightening boundary group are not higher than the corresponding boundaries in the cutting inhibition base boundary group, and the load recovery confirmation time is not shorter than the corresponding time in the cutting inhibition base boundary group.

[0103] If the cutting stall risk result of the previous control cycle is boundary hold, the protection pressure risk module of this control cycle adopts the protection pressure base boundary group; if the cutting stall risk result of the previous control cycle is boundary tightening, the protection pressure risk module of this control cycle adopts the protection pressure tightening boundary group. The first and second pressure entry boundaries in the protection pressure tightening boundary group are not higher than the corresponding boundaries in the protection pressure base boundary group, and the recovery confirmation time is not shorter than the corresponding time in the protection pressure base boundary group.

[0104] If the cutting stall risk result of the previous control cycle is unloading recovery, or if any risk result is safety lockout, the circuit control board 150 will not continue to execute ordinary boundary modulation, but will instead form an unloading recovery request or a safety lockout request according to the joint control relationship.

[0105] The specific parameters in the basic boundary group and the tightening boundary group are determined based on the combined working conditions of simulated ear canal pressure, normal cutting, dense hair cutting, earwax simulation material blockage, and simultaneous increase of pressure and load, and are written into the parameter package.

[0106] This embodiment modulates the effective boundary group of another risk module in the current control cycle using the risk results from the previous control cycle. This allows both risk modules to use the pre-determined boundary group at the beginning of the current control cycle and generate risk results in parallel within the same control cycle. This avoids circular dependencies or repeated boundary changes caused by the two risk modules modifying each other's judgment boundaries within the same control cycle. When a single pressure risk or a single blockage risk has already appeared in the previous control cycle, the other risk module tightens the boundary group in the current control cycle, thereby identifying the combined risk of both pressure and blockage increasing in advance.

[0107] The effective boundary set includes the entry boundary, exit boundary, duration boundary, and recovery time boundary. The boundary modulation result is limited to the minimum and maximum values ​​specified in the parameter package and is maintained for at least one complete control cycle. When two types of risk results continuously maintain the boundary and reach the boundary recovery time, the factory basic boundary set is restored in the next control cycle; if a new risk result occurs during the recovery process, the recovery is stopped and remodulation is performed.

[0108] Both modules use the same parameter version number, and the difference in timestamps of the input data must not exceed the allowed synchronization time. If the parameter versions are inconsistent or the input data is invalid, the circuit control board 150 generates a safety lockout request; if the protection pressure risk module fails to generate a protection pressure risk result within the specified output time limit, or if the cutting resistance risk module fails to generate a cutting resistance risk result within the specified output time limit when the flag is invalid in the benchmark establishment, the circuit control board 150 generates a safety lockout request.

[0109] The joint control relationship is as follows: when both types of risk outcomes are boundary hold, a stable pruning request is generated; when one type is boundary tightening and the other is boundary hold, a tightening buffer request is generated; when the protection pressure risk outcome is boundary hold and the cutting stall risk outcome is unloading recovery, an unloading recovery request is generated; when the protection pressure risk outcome is boundary tightening and the cutting stall risk outcome is boundary tightening or unloading recovery, a safety lockout request is generated; when any risk outcome is safety lockout, sampling or reference failure, reference establishment timeout, calculation timeout, or fault code validity, a safety lockout request is generated.

[0110] When multiple requests are valid at the same time, their priorities are as follows: security lock request, unload recovery request, tighten buffer request, and stability pruning request.

[0111] Example 7, as Figure 4 and Figure 5 As shown, the underlying state machine includes a shutdown state, a low-brightness preparation state, a low-speed probing state, a stable pruning state, a tightening buffer state, an unloaded recovery state, and a safety locking state, and each state is mutually exclusive.

[0112] In the off state, the lighting element 600 and the drive motor 160 are off. After the switch 130 is activated, it enters a low-brightness preparation state.

[0113] In the low-brightness preparation state, the lighting component 600 is at low brightness, the drive motor 160 is turned off, and the circuit control board 150 sequentially performs lighting self-test, fixed protective cover position detection, power supply voltage detection, and touch reference confirmation. If any detection fails or the self-test times out, it enters the safety lockout state.

[0114] In low-speed trial mode, drive motor 160 operates according to the trial drive duty cycle, and the benchmark establishment in progress flag is valid. After the installation judgment of the active inner blade 300 and the no-load benchmark establishment are completed, the benchmark establishment in progress flag is cleared. When the no-load benchmark is valid, and the protection pressure risk result and the cutting resistance risk result are both boundary maintained, the stable trimming state is entered; when the benchmark establishment fails and the protection pressure risk result is safety lockout, the safety lockout state is entered.

[0115] In stable trimming mode, lighting element 600 remains constantly lit, and drive motor 160 operates according to the stable trimming drive duty cycle. Upon receiving a tightening buffer request, unloading recovery request, or safety lock request, it enters the corresponding state.

[0116] In the tightened buffer state, the illuminator 600 is at high brightness, and the drive motor 160 operates at a drive duty cycle lower than the stable trim drive duty cycle. Once the normalized pressure value drops below the first pressure exit boundary and remains below it for the recovery confirmation time, the pressure state returns to an in-position, unpressurized state. After the normalized load value drops below the load recovery boundary and remains below it for the load recovery confirmation time, the system returns to the low-speed probing state. The tightened buffer state continues to operate only when one type of risk recovers; if recovery does not occur simultaneously after the allowable tightened buffer duration, the system enters a safety lockout state. The load recovery confirmation time is determined based on the filter window and the load drop test.

[0117] In the unloaded recovery state, drive motor 160 is off, and lighting element 600 outputs a flashing unloaded or cleaning indicator. The normal static range for shutdown is determined by continuous static sampling calibration of motor load detection element 800 when drive motor 160 is off. If the static output exceeds the defined range, the load detection branch is considered abnormal.

[0118] After the user removes the cutting head, inspects or cleans it, and performs a reset operation, the circuit control board 150 verifies the status of the fixed protective cover 400 in place, the in-place unpressurized state, and the static output of the shutdown. If the verification is successful, it returns to the low-speed probing state; if the reset is not completed within the allowed unloading recovery time, or if an abnormal load is still detected after the reset, it enters the safety lockout state. In the unloading recovery state, the moving inner blade 300 is not driven to reverse.

[0119] In the safety lockout state, drive motor 160 remains off and is prohibited from starting. After all fault flags causing the lockout are cleared and the user performs a reset operation, the following checks are performed in sequence: fixed protective cover in place verification, lighting self-test, touch pressure reference confirmation, low-speed test, and no-load reference confirmation; only after all the above checks are passed can the stable trimming state be entered.

[0120] Switch off, hardware overcurrent cutoff, and power protection cutoff have the highest execution priority. When the switch is kept on, the priority of the operating states is as follows: safety lockout, unload recovery, tightening buffer, stabilization trimming, low-speed probing, and low-brightness preparation. After the switch is off, the safety lockout fault flag can be retained until the next startup review.

[0121] The state machine output includes at least the current status code, lighting output code, drive motor operation command, protection level, fault code, parameter version number, and timestamp.

[0122] Example 8, as Figure 6 As shown, the factory calibration includes mechanical structure testing, protective structure testing, lighting testing, pressure testing and calibration, load testing and calibration, and state machine joint testing in sequence.

[0123] Mechanical structure testing includes the installation, anti-detachment, and radial runout of the movable inner blade 300; the dimensions and fit of the hair infeed gap 440 and the fixed shearing edge 450; no-load friction; and simulated hair cutting. Protective structure testing includes the positioning of the fixed protective cover 400, pressure displacement, indentation recovery, contact outside the designed shearing area, and pressure on the ear canal model. Illumination testing includes low brightness, constant brightness, high brightness, flickering, and illumination current testing.

[0124] The contact resistance of the fixed protective cover 400 is collected under the following conditions: not in place, in place but not under pressure, and under the first and second pressure loads. This data is used to establish the contact resistance reference, contact resistance reference resistance, judgment range, pressure entry boundary, pressure exit boundary, and confirmation time.

[0125] The load calibration collects motor current and recovery time under no-load, normal cutting, dense hair, entanglement trend and controlled stall conditions, respectively, to form no-load reference, blade installation current range, blade installation fluctuation range, load entry boundary, load recovery boundary, stall entry boundary and corresponding confirmation time.

[0126] The state machine joint detection includes normal trimming, individual pressure, individual blockage, simultaneous increase of pressure and load, loosening of fixed protective cover, invalid data, calculation timeout, and hardware protection action.

[0127] A valid parameter package is generated when all tests and calibrations pass; if any test or calibration fails, a test or calibration fault code is output, a valid parameter package is not generated, and an exception is written to the error log. The parameter package must include at least the parameter name, parameter value, unit, minimum and maximum boundary values, confirmation time, recovery time, version number, checksum, and calibration date.

[0128] Upon power-on, the circuit control board 150 reads and verifies the parameter package. If the parameter package is missing, the version is mismatched, verification fails, or the parameters exceed the allowable range, a parameter anomaly fault flag is generated, and entry into stable trimming mode is prohibited. The anomaly log includes at least the anomaly type, occurrence status, relevant sampled values, fault code, parameter version number, and timestamp.

[0129] The embodiments of the present invention have been described above. Any equivalent substitutions or modifications made by those skilled in the art to the related structures, connections, or control processes without departing from the concept of the present invention should fall within the protection scope of the present invention.

Claims

1. A head-illuminated ear hair trimmer, characterized in that, It includes a housing, a tool holder, a drive motor, a transmission shaft, a movable inner blade, a fixed protective cover, lighting components, a pressure detection component, a motor load detection component, and a circuit control board; The drive motor drives the movable inner blade to move relative to the fixed protective cover through the transmission shaft. The fixed protective cover is disposed outside the movable inner blade and forms a hair infeed gap. The edge of the hair infeed gap forms a fixed shearing edge that engages with the movable inner blade for shearing. The lighting element emits light towards the front of the fixed protective cover and the area corresponding to the hair inlet gap; The pressure detection device is used to obtain the pressure information of the fixed protective cover, and the motor load detection device is used to obtain the cutting load information of the movable inner blade; The circuit control board is used to generate protection pressure risk results and cutting resistance risk results based on the pressure information and cutting load information within the same control cycle, determine the cutting resistance judgment boundary of the current control cycle based on the protection pressure risk results of the previous control cycle, determine the protection pressure judgment boundary of the current control cycle based on the cutting resistance risk results of the previous control cycle, and control the lighting element and the drive motor based on the combination relationship between the protection pressure risk results and the cutting resistance risk results of the current control cycle.

2. The head-illuminated ear hair trimmer according to claim 1, characterized in that, It also includes a fixed protective sleeve and a cutter head mounting position. The cutter head mounting position is located at the front end of the cutter bar. The fixed protective sleeve is installed at the cutter head mounting position and is fixedly connected to the cutter bar. The fixed protective cover is installed at the front end of the fixed protective sleeve. The fixed protective cover does not rotate circumferentially relative to the blade holder and the fixed protective sleeve. The root of the fixed protective cover generates radial or axial elastic displacement under the limiting fit between the fixed protective sleeve and the fixed protective cover. The limiting fit restricts the elastic displacement, so that the areas on the fixed protective cover other than the area forming the shearing fit relationship are kept at a distance from the movable inner blade.

3. The head-illuminated ear hair trimmer according to claim 2, characterized in that, The fixed protective cover includes a fixed outer blade part, the fixed protective sleeve includes a light-transmitting part, the fixed outer blade part is made of metal material, and the bristle inlet gap and the fixed shearing edge are formed on the fixed outer blade part; The cutting edge of the movable inner blade forms a close shearing relationship or a gap shearing relationship with the fixed shearing edge; Under the aforementioned close-fitting shearing relationship, the movable inner blade has an elastic blade arm or an elastic cutting portion, and the cutting edge is made to adhere to the inner side of the fixed shearing edge by the elastic deformation of the elastic blade arm or the elastic cutting portion. Under the aforementioned gap shearing relationship, the cutting edge of the movable inner blade and the fixed shearing edge maintain a gap determined according to the ear hair diameter, the radial runout of the movable inner blade, the inner diameter of the fixed protective cover, the coaxiality of the drive shaft, and the assembly tolerance.

4. The head-illuminated ear hair trimmer according to claim 3, characterized in that, The lighting element is fixed to the fixed protective sleeve, the cutter head mounting position, or the fixed protective cover at a location that does not rotate with the drive shaft, and the light emission direction of the lighting element is towards the hair inlet gap and its corresponding shearing area. A light-emitting gap is formed between the lighting element and the light-transmitting part. The lighting element is connected to the circuit control board through a flexible wire. The flexible wire is arranged along the area of ​​the fixed protective sleeve or the blade bar that does not rotate with the drive shaft, and is spaced apart from the movement path of the drive shaft and the movable inner blade.

5. A head-illuminated ear hair trimmer according to any one of claims 2 to 4, characterized in that, The pressure detection component includes a conductive contact and an elastic conductive sheet. The base of the fixed protective cover is provided with a pressure-bearing and force-transmitting part. The pressure-bearing and force-transmitting part forms a circumferentially extending pressure-bearing ring surface, which is disposed opposite to the elastic conductive sheet. When the fixed protective cover is subjected to radial pressure, the pressure-bearing and force-transmitting part generates radial displacement at the root of the fixed protective cover corresponding to the pressure position, and pushes the elastic conductive sheet to deform. When the fixed protective cover is subjected to axial pressure, the pressure-bearing and force-transmitting part generates axial displacement and pushes the elastic conductive sheet to press the conductive contact. A dirt-blocking and sealing structure is provided on the outer side of the contact area between the conductive contact and the elastic conductive sheet.

6. A head-illuminated ear hair trimmer according to claim 5, characterized in that, The circuit control board detects the equivalent contact resistance between the conductive contact and the elastic conductive sheet through a contact resistance sampling branch. When the fixed protective cover is not installed in place, the equivalent contact resistance is in the non-in-place judgment range; when the fixed protective cover is installed in place and not under pressure, the equivalent contact resistance is in the in-place judgment range; when the fixed protective cover is pressed against the conductive contact by the elastic conductive sheet, the equivalent contact resistance is in the contact pressure judgment range. The non-in-position judgment range, the in-position judgment range, and the touch pressure judgment range do not overlap with each other, and an isolation zone is set between adjacent judgment ranges; The circuit control board forms a normalized pressure value based on the ratio of the difference between the contact resistance reference when the fixed protective cover is installed in place and not under pressure and the current equivalent contact resistance to the difference between the contact resistance reference and the pressure reference resistance. The circuit control board generates a contact state based on the normalized contact value. The contact state includes an in-position unpressed state, a contact risk increased state, an effective contact state, and a continuous contact state. When the normalized pressure value is lower than the first pressure entry boundary, an in-situ unpressurized state is formed; When the normalized pressure value reaches the first pressure entry boundary but is lower than the second pressure entry boundary, and continues to reach the first confirmation time, a pressure risk increase state is formed; if the first confirmation time has not been reached, the in-place unpressurized state is maintained. When the normalized pressure value reaches the second pressure entry boundary but the duration does not reach the second confirmation time, an effective pressure state is formed; when the normalized pressure value reaches the second pressure entry boundary and continues to reach the second confirmation time, a continuous pressure state is formed. When in the continuous pressing state, the normalized pressing value drops below the second pressing exit boundary and continues to reach the recovery confirmation time, then it is reduced to the effective pressing state; when in the effective pressing state or the pressing risk rising state, the normalized pressing value drops below the first pressing exit boundary and continues to reach the recovery confirmation time, then it is reduced to the in-place unpressed state. The current pressure state is maintained until the recovery confirmation time has been reached, with the first pressure exit boundary lower than the first pressure entry boundary and the second pressure exit boundary lower than the second pressure entry boundary.

7. A head-illuminated ear hair trimmer according to claim 6, characterized in that, The motor load detection device includes a motor current sampling branch for collecting the operating current of the drive motor, and the circuit control board is also connected to a lighting current detection branch for collecting the operating current of the lighting device. When the fixed protective cover is in place, the touch-press state is the in-place but not pressurized state, the current power supply voltage is within the working voltage range, and the working current of the lighting component is within the lighting current judgment range, the circuit control board controls the drive motor to enter a low-speed probing state. In the low-speed testing state, the circuit control board shields the starting surge of the drive motor, and judges the installation status of the movable inner blade based on the average value of the working current and the fluctuation of the working current continuously collected after the surge shielding ends. When the average value of the operating current exceeds the blade installation current range, or when the fluctuation of the operating current exceeds the blade installation fluctuation range, an abnormal blade installation state is formed and the establishment of an unloaded reference is prohibited; when the installation state of the active blade is normal, and the fluctuation of the operating current does not exceed the unloaded reference establishment boundary and continues to reach the reference confirmation time, the unloaded reference is established based on the continuously collected operating current. The allowed low-speed test time is the total allowed time from entering the low-speed test state to forming a valid no-load reference. The allowed low-speed test time is determined based on the surge shielding start time, the determination time of the active blade installation status, and the reference confirmation time. The circuit control board determines the dynamic stall reference current based on the stall reference current calibrated under the reference supply voltage and the current supply voltage, and forms a normalized load value based on the ratio of the difference between the current operating current and the no-load reference to the difference between the dynamic stall reference current and the no-load reference. The circuit control board forms the load status based on the normalized load value, load duration, and load recovery time. When the normalized load value is lower than the first load entry boundary, a normal cutting state is formed; When the normalized load value reaches the first load entry boundary and drops below the first load exit boundary within the normal recovery time, the normal cutting state is maintained; if the load value fails to drop below the first load exit boundary after the normal recovery time, a slow load recovery state is formed. When the normalized load value reaches the second load entry boundary and continues to reach the blockage confirmation time, a blockage trend state is formed; if the blockage confirmation time has not yet been reached, the slow load recovery state is formed or maintained. When the normalized load value reaches the stall entry boundary and continues to reach the stall confirmation time, or when the drive circuit of the drive motor triggers hardware overcurrent protection, a stall state is formed. The first load exit boundary is the load recovery boundary and is lower than the first load entry boundary, and the second load entry boundary is higher than the first load entry boundary and lower than the stall entry boundary.

8. A head-illuminated ear hair trimmer according to claim 7, characterized in that, The circuit control board includes a protection module for pressure risk and a cutting resistance risk module. The protective pressure risk module is used to form a boundary holding, boundary tightening, or safety locking as the result of the protective pressure risk based on the fixed protective cover's in-position status, the normalized pressure value, the pressure duration, the number of pressure jitters, the pressure release recovery time, the sampling validity flag, and the pressure fault code. The cutting stall risk module is used to form boundary holding, boundary tightening, unloading recovery or safety locking as the result of the cutting stall risk based on the normalized load value, the no-load reference, the load duration, the load recovery time, the number of repeated load events, the reference validity flag and the load fault code. In the low-speed trial state and when the no-load reference has not yet been established, the cutting stall risk module forms a reference establishment in progress flag, does not calculate the normalized load value, and does not form the cutting stall risk result; The protection pressure risk module continues to generate the protection pressure risk result; After the no-load reference is established and the reference validity flag is valid, the flag in the reference establishment is cleared. The protection pressure risk module and the cutting jamming risk module form their respective risk results for the current cycle in parallel within the same control cycle based on the data associated with the same control cycle. At the beginning of each control cycle, the circuit control board determines the effective boundary group of the cutting jamming risk module in the current control cycle based on the protection pressure risk result of the previous control cycle, and determines the effective boundary group of the protection pressure risk module in the current control cycle based on the cutting jamming risk result of the previous control cycle. When the results of the dual-risk parallel analysis are first generated, the protection pressure risk module and the cutting resistance risk module adopt the factory-set basic boundary group; the modulation result of the effective boundary group maintains at least one complete control cycle and is limited to the boundary minimum and boundary maximum values ​​specified in the parameter package.

9. A head-illuminated ear hair trimmer according to claim 8, characterized in that, The circuit control board generates control requests based on the combination of the protection pressure risk results and the cutting resistance risk results. The control requests include stable trimming requests, tightening buffer requests, unloading recovery requests, and safety lockout requests. When the flag is valid during the benchmark establishment, the stable pruning request is not generated, and the circuit control board maintains the low-speed probing state. When both the protection pressure risk result and the cutting hindrance risk result are boundary-preserved, the stable trimming request is formed; When the protection pressure risk result is boundary tightening and the cutting stall risk result is boundary holding, or when the protection pressure risk result is boundary holding and the cutting stall risk result is boundary tightening, the tightening buffer request is formed. When the protection pressure risk result is boundary preservation and the cutting blockage risk result is unloading recovery, the unloading recovery request is generated; When the protection pressure risk result is boundary tightening, and the cutting blockage risk result is boundary tightening or unloading recovery, the safety lockout request is formed; The safety lockout request is generated when any of the following situations occur: the protection pressure risk result is a safety lockout; the cutting resistance risk result is a safety lockout; the sampling validity flag of the protection pressure risk module is invalid; after the no-load reference is established, the reference validity flag of the cutting resistance risk module changes from valid to invalid; the low-speed test state has exceeded the allowed low-speed test time and still has not formed a valid no-load reference. The protection pressure risk module failed to generate the protection pressure risk result within the output time limit determined by the control cycle; When the flag is invalid during the benchmark establishment, the cutting stall risk module fails to generate the cutting stall risk result within the output time limit determined by the control cycle; Or the fault code of any module is valid; When multiple control requests are valid simultaneously, the circuit control board executes the control request with the highest protection priority in the order of the safety lock request, the unload recovery request, the tighten buffer request, and the stability trim request.

10. A head-illuminated ear hair trimmer according to claim 9, characterized in that, The circuit control board controls the lighting element and the drive motor through a low-level state machine. The control states of the low-level state machine include off state, low brightness preparation state, low speed probing state, stable trimming state, tightening buffer state, unloading recovery state, and safety lock state. Each control state is mutually exclusive. In the off state, the lighting element and the drive motor are off; in the low-brightness preparation state, the lighting element is at low brightness and the drive motor is off. In the low-speed trial state, the drive motor operates according to the trial drive duty cycle; In the stable trimming state, the lighting element is constantly lit and the drive motor operates according to the stable trimming drive duty cycle. In the tightening buffer state, the lighting element is bright, and the drive motor operates at a drive duty cycle lower than the stable trimming drive duty cycle; in the unloading recovery state, the drive motor is turned off, and the lighting element outputs a flashing unloading or cleaning prompt. In the safety lockout state, the drive motor remains off and is prohibited from starting. When the operating current of the lighting element is within the lighting current judgment range, the lighting element outputs a fault indication. When exiting the tightened buffer state, the normalized pressure value drops below the first pressure exit boundary and continues to reach the recovery confirmation time, so that the pressure state is restored to the in-place unpressed state. After the normalized load value drops below the load recovery boundary and continues to reach the load recovery confirmation time, the underlying state machine returns to the low-speed probing state. In the unloaded recovery state, after the circuit control board receives the user's reset operation and detects that the fixed protective cover is in place, the touch state is in place without pressure, and the static output of the motor load detection device is within the normal range of shutdown, the underlying state machine returns to the low-speed probing state. When the tightening buffer state or the unloading recovery state fails to meet the exit condition within their respective allowed durations, the underlying state machine enters the safety locking state. In the safety lock state, after all fault flags that caused the safety lock have been cleared and the circuit control board receives the user's reset operation, the underlying state machine sequentially performs the following checks: fixed protective cover in place verification, lighting self-test, touch pressure reference confirmation, low speed test, and no-load reference confirmation. Only after all the above checks are passed can the stable trimming state be entered.

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