Hand waving induction device for kitchen appliances and range hood

Abstract

The utility model relates to a kind of waving hand induction device and range hood for kitchen appliance, waving hand induction device includes waving hand induction module and controller, the waving hand induction module includes infrared emitter and infrared receiver, the infrared emitter and infrared receiver are electrically connected with the controller, the infrared emitter of the waving hand induction module has at least two adjacent arrangements, one infrared receiver is arranged between adjacent two the infrared emitter, adjacent two the infrared emitter and the infrared receiver located in the middle thereof jointly constitute a waving hand induction module, the waving hand induction module is configured as: adjacent two the infrared emitter share an infrared receiver, and adjacent two infrared emitters emit infrared signal outward in the form of staggered emission. Advantage lies in: waving hand induction module can be arranged at close range to reduce product main body trepanning processing, and can ensure gesture recognition accuracy.

Description

Technical Field

[0001] This utility model relates to the field of kitchen appliance technology, and in particular to a gesture sensing device and a range hood for kitchen appliances. Background Technology

[0002] With the increasing demand for smart appliances, kitchen appliances such as range hoods, dishwashers, and steam ovens often employ contactless control methods to display and control product functions. Taking range hoods as an example, existing range hoods have infrared transmitting and receiving probes facing the outside of the range hood casing. These probes transmit and receive signals, respectively. When a user waves their arm within the sensing range, the infrared receiving probe receives the start signal and transmits it to the control panel, which then activates the range hood. However, existing range hoods typically only use one set of infrared transmitting and receiving probes, resulting in overly simplistic control commands that cannot achieve complete operation of the range hood.

[0003] To address the aforementioned technical problems, Chinese invention patent application CN201510011826.2 discloses a non-contact control method for a range hood. The main solution involves installing several infrared emitting diodes that emit infrared light and several infrared receiving sensors that detect infrared light reflected back from the outside on the range hood. The infrared emitting diodes and infrared receiving sensors are in one-to-one correspondence. The method includes the following steps: several infrared emitting diodes sequentially emit infrared light; several infrared receiving sensors sequentially detect the infrared light intensity when the corresponding infrared emitting diode is emitting light and the background infrared light intensity when the corresponding infrared emitting diode is extinguished; real-time recognition of control gestures based on the infrared light intensity detected by each infrared receiving sensor; and generation of control commands based on the control gestures to control the range hood.

[0004] However, in existing technologies, to achieve multi-gesture recognition, range hoods typically require multiple sets of one-to-one infrared transmitters and receivers, which has significant shortcomings in practical applications. First, each transmitter and receiver requires independent installation space, and to ensure sensing accuracy, a certain distance must be maintained between them. This necessitates reserving multiple windows or openings that are relatively far apart on the product body, which is particularly difficult and costly for metal panels, and also affects the product's aesthetics. Second, the layout of multiple components increases structural complexity, leading to low production and assembly efficiency, and may weaken the panel's strength due to excessive holes. Furthermore, this design has poor adaptability to the compact structure of kitchen appliances, limiting the flexibility of industrial design. Utility Model Content

[0005] The first technical problem to be solved by this utility model is to provide a hand gesture sensing device for kitchen appliances that can be arranged in close proximity to reduce the need for opening holes in the main body of the product, while ensuring the accuracy of gesture recognition, in light of the current state of the technology.

[0006] The second technical problem to be solved by this utility model is to provide a range hood that applies the above-mentioned hand gesture sensing device, in view of the current state of the prior art.

[0007] The technical solution adopted by this utility model to solve the first technical problem is as follows: a wave sensing device for kitchen appliances, including a wave sensing module and a controller. The wave sensing module includes an infrared transmitter and an infrared receiver. Both the infrared transmitter and the infrared receiver are electrically connected to the controller. The wave sensing module has at least two infrared transmitters arranged adjacent to each other. An infrared receiver is arranged between two adjacent infrared transmitters. The two adjacent infrared transmitters and the infrared receiver located between them together constitute a wave sensing module. The wave sensing module is configured such that two adjacent infrared transmitters share one infrared receiver, and the two adjacent infrared transmitters emit infrared signals outward in a staggered manner.

[0008] The aforementioned "staggered transmission" refers to the situation where two adjacent infrared transmitters do not transmit infrared signals simultaneously, i.e., a temporal "stagger." For example, a controller can control transmitters A and B to operate alternately. Transmitter A might first transmit an infrared pulse while transmitter B is off; then transmitter B might transmit while transmitter A is off, and so on. This staggered transmission by the two infrared transmitters can detect a hand gesture, and the waveform received by the infrared receiver generally exhibits a structure similar to a normal distribution.

[0009] The gesture sensing device for kitchen appliances effectively solves the manufacturing complexity and aesthetic problems caused by the need for multiple independent components for multi-gesture recognition by arranging at least two infrared transmitters adjacent to each other and sharing a central infrared receiver to form a compact gesture sensing module. Because the transmitter and receiver are integrated close together, the number of openings on the product panel is significantly reduced, lowering the processing difficulty and cost of the metal panel, while enhancing panel strength and overall aesthetics. Furthermore, through staggered transmission (i.e., alternating infrared signal transmission), the infrared receiver can capture signal changes at different points in time during the wave, forming a waveform similar to a normal distribution, thereby accurately identifying the gesture trajectory and direction, ensuring the accuracy and reliability of gesture recognition. This design improves the adaptability of kitchen appliance structures, simplifies assembly processes, and increases production efficiency and industrial design flexibility.

[0010] As an improvement, the distances between two adjacent infrared transmitters and the infrared receiver located between them are equal. This symmetrical layout ensures that the physical characteristics of the two sensing channels are essentially the same, making the controller more accurate and reliable in comparing the timing and intensity of the two signals, and reducing the risk of misjudgment of direction.

[0011] As an improvement, the infrared receiver is a phototransistor. Phototransistors have high sensitivity to infrared signals and a fast response speed, making them ideal for detecting rapid hand movements. Furthermore, their simple structure and low cost facilitate large-scale production applications.

[0012] As an improvement, a circuit board is also included. Each infrared emitter and receiver is mounted on the back of the circuit board via a surface-mount connection. The circuit board also has a light-transmitting hole extending from its front to its back. The sensing ends of each infrared emitter and receiver are located in the corresponding light-transmitting holes on the circuit board. This structural design allows the infrared emitters and receivers to be hidden behind the circuit board, sensing through the light-transmitting holes. Visually, only a small hole or light-shielding element is visible, resulting in a strong overall integrity. This surface-mount packaging design is suitable for the assembly line operations of modern electronics manufacturing, improving production efficiency and product consistency.

[0013] To better guide the light path and prevent stray light interference, especially shielding against ambient light interference from non-sensing areas such as the sides, an improvement includes a fixed housing. The wave-sensing module and controller are all housed within this fixed housing. The fixed housing comprises a front half and a rear half that interlock. A light-transmitting channel extending front to back is constructed on the front half, aligning with a light-transmitting hole on the circuit board. The rear end of the light-transmitting channel connects to the light-transmitting hole on the circuit board, and a light-shielding element made of semi-transparent black material is also provided at the front end of the light-transmitting channel. The fixed housing provides mechanical support, positioning, and physical protection for the entire sensing device. The light-transmitting channel on the fixed housing effectively constrains the light path, reducing the entry of stray light. The semi-transparent black light-shielding element at the front end efficiently transmits infrared light (for sensing) while significantly attenuating visible light (preventing internal components from being seen and reducing visible light interference), further optimizing sensing performance.

[0014] The aforementioned "semi-transparent black material" is a material with selective transmittance characteristics for visible and infrared light. It is opaque or has very low transparency (appearing black) in the visible light band, but has high transmittance in the infrared band (especially the infrared wavelength used by the device). Examples include black polycarbonate (PC) or acrylonitrile-styrene-butadiene copolymer (ABS) plastics, which, by adding special dyes or pigments, exhibit strong absorption of visible light but weak absorption of specific wavelengths of infrared light. The design of the aforementioned light-shielding component ensures normal sensing function while concealing internal components, maintaining the overall integrity and aesthetics of the product's appearance.

[0015] As an improvement, the visible light transmittance of the light-shielding component is less than 20%, and the infrared light transmittance is greater than or equal to 70%. The design of the light-shielding component ensures that it can effectively hide the internal components (low visible light transmittance, black appearance) while ensuring that the infrared sensing signal has sufficient intensity (high infrared light transmittance), making the hand gesture sensing function sensitive and reliable.

[0016] As an improvement, each light-transmitting channel on the front half-shell corresponding to a gesture sensing module protrudes forward relative to the main body of the front half-shell. The front part of the front half-shell also has a light-shielding sleeve fitted over the protruding portion of each light-transmitting channel. The light-shielding element is located on the light-shielding sleeve at least in an area opposite to the front port of the light-transmitting channel. Designing the light-shielding functional component as a separate kit simplifies the mold structure and assembly process of the front half-shell.

[0017] To prevent light emitted by one infrared transmitter from directly leaking or reflecting into an adjacent infrared receiver, causing signal interference and misjudgment (i.e., preventing optical crosstalk), the circuit board has a strip-shaped opening in the area between adjacent infrared transmitters and receivers to isolate them. A light-shielding plate, which can be embedded in the strip-shaped opening, is correspondingly provided on the front or rear half of the shell. The strip-shaped opening and the light-shielding plate physically isolate the direct optical path between adjacent optical components, ensuring that the light emitted by each transmitter is mainly received by the corresponding receiver after reflection from external space, greatly reducing internal crosstalk and improving the accuracy of the sensing logic.

[0018] Considering that the substrate of the circuit board itself has a certain light transmittance, simply creating a strip-shaped opening will still allow light to pass through. Therefore, the sidewalls of the opening are metallized (e.g., copper plating as a light-shielding layer) to achieve light isolation; that is, a light-shielding layer is also provided at the edge of the strip-shaped opening. The metallization of the sidewall edges of the strip-shaped opening is used to isolate crosstalk interference between the infrared emitter and the phototransistor through the PCB. After taking these measures, the circuit board itself can isolate most of the crosstalk interference between the emitter and the phototransistor.

[0019] The technical solution adopted by this utility model to solve the second technical problem is: a range hood, including a housing and a hand gesture sensing device disposed on the housing, wherein the hand gesture sensing device adopts the aforementioned hand gesture sensing device for kitchen appliances.

[0020] Compared with existing technologies, the advantages of this invention are as follows: The hand gesture sensing device for kitchen appliances of this invention forms a compact hand gesture sensing module by arranging at least two infrared transmitters adjacent to each other and sharing a central infrared receiver. This effectively solves the processing complexity and aesthetic problems caused by the need for multiple independent components for multi-gesture recognition. Because the transmitter and receiver are integrated close together, the number of openings on the product panel is significantly reduced, lowering the processing difficulty and cost of the metal panel, while enhancing panel strength and overall aesthetics. Furthermore, through staggered transmission (i.e., alternating infrared signal transmission), the infrared receiver can capture signal changes at different points in time during the hand gesture, forming a waveform similar to a normal distribution, thereby accurately identifying the gesture trajectory and direction, ensuring the accuracy and reliability of gesture recognition. This design improves the adaptability of kitchen appliance structures, simplifies assembly processes, and increases production efficiency and industrial design flexibility. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the hand gesture sensing device according to an embodiment of the present utility model;

[0022] Figure 2 This is a sectional perspective view of the hand gesture sensing device according to an embodiment of the present utility model;

[0023] Figure 3 This is an exploded view of the hand gesture sensing device according to an embodiment of the present invention;

[0024] Figure 4 This is a front view of the circuit board of the hand gesture sensing device according to an embodiment of the present invention. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] In the specification and claims of this utility model, terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of this utility model. However, the use of these terms is merely for the purpose of explanation and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this utility model can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0027] Figures 1-4 A preferred embodiment of the present invention, a gesture sensing device for kitchen appliances and a range hood, is shown. The gesture sensing device for kitchen appliances includes a gesture sensing module 1, a controller, a circuit board 13, and a mounting housing 2. The gesture sensing module 1 includes two adjacent infrared transmitters 11 and an infrared receiver 12 located between the two infrared transmitters 11. Both the infrared transmitters 11 and the infrared receiver 12 are electrically connected to the controller. Specifically, the two infrared transmitters 11 are arranged sequentially in the horizontal direction and symmetrically about the infrared receiver 12 located in the middle, such that the distance between each infrared transmitter 11 and the middle infrared receiver 12 is equal, thereby ensuring that the physical characteristics of the sensing channel are consistent.

[0028] The hand gesture sensing module 1 is configured to operate in a staggered transmission mode: the controller controls two infrared transmitters 11 to work alternately, that is, when the first infrared transmitter 11 emits an infrared signal, the second infrared transmitter 11 is turned off; subsequently, when the second infrared transmitter 11 emits an infrared signal, the first infrared transmitter 11 is turned off. This alternating transmission cycles at a certain frequency. When the user's hand waves within the sensing range, the infrared receiver 12 receives the reflected infrared signal. Due to the staggered operation of the transmitters, the signal waveform output by the receiver will exhibit a change similar to a normal distribution. By analyzing the timing, intensity, and peak sequence of this waveform, the controller can accurately identify the direction and trajectory of the gesture (such as a hand gesture from left to right or from right to left).

[0029] The infrared receiver 12 preferably uses a phototransistor, which has high sensitivity and fast response characteristics, making it suitable for detecting rapid hand movements. Each infrared emitter 11 and infrared receiver 12 is soldered to the back of the circuit board 13 in a surface mount package. The front of the circuit board 13 has multiple light-transmitting holes 130 that extend from the front to the back. The sensing end (i.e., the light-emitting part) of each infrared emitter 11 and the sensing end (i.e., the light-receiving part) of each infrared receiver 12 is aligned with a light-transmitting hole 130, allowing infrared signals to be emitted or received through the light-transmitting holes 130.

[0030] See Figure 2 and Figure 3The fixed housing 2 provides mechanical support and protection for the wave sensing device, and includes a front half-housing 21 and a rear half-housing 22 that snap together. The wave sensing module 1 and the controller are both installed inside the fixed housing 2. The front half-housing 21 has multiple light-transmitting channels 210 that extend front to back, with the rear port of each channel 210 connected to a light-transmitting hole 130 on the circuit board 13, while the front port faces the external sensing area. The inner walls of the light-transmitting channels 210 are smooth to facilitate light transmission. A light-shielding element 41 is provided at the front port of the light-transmitting channel 210. This light-shielding element 41 is made of a semi-transparent black material (specifically, it can be made of semi-transparent black PC material itself, or it can be coated with a semi-transparent black oil film), with a visible light transmittance of less than 20% (preferably less than 10%) and an infrared light transmittance of greater than or equal to 70% (preferably greater than 80%). This design makes the light-shielding element 41 appear black under visible light, effectively hiding internal components while ensuring efficient transmission of infrared signals.

[0031] In addition to semi-transparent black polycarbonate (PC) or ABS plastic, the light-shielding component 41 can also use other materials that are highly transparent to infrared light and low transparent to visible light, such as black silicone or glass fiber reinforced plastic with added special infrared transmission dyes.

[0032] To further optimize optical path isolation, each light-transmitting channel 210 (in this embodiment, there are three light-transmitting channels 210, corresponding to two infrared emitters 11 and one infrared receiver 12, respectively) on the front half shell 21 protrudes forward relative to the main body of the front half shell 21. A light-shielding sleeve 4 is also fitted over the front of the front half shell 21, covering all the forward-protruding light-transmitting channels 210. The area on the light-shielding sleeve 4 corresponding to the front port of the light-transmitting channel 210 is composed of the aforementioned semi-transparent black material light-shielding element 41. The light-shielding sleeve 4 can be manufactured independently and then assembled onto the front half shell 21, simplifying the mold structure.

[0033] To prevent optical crosstalk between the infrared emitter 11 and the infrared receiver 12 through the substrate of the circuit board 13, a strip-shaped opening 131 is provided on the circuit board 13 in the area between adjacent infrared emitters 11 and infrared receivers 12. This strip-shaped opening 131 penetrates the circuit board 13, and its edge is provided with a light-shielding layer (e.g., formed by metallization such as copper plating) to completely block light transmission. Correspondingly, a light-shielding plate 211 adapted to the contour of the strip-shaped opening 131 is provided on the inner side of the front half-shell 21 or the rear half-shell 22. This light-shielding plate 211 is embedded in the strip-shaped opening 131 during assembly, further ensuring physical isolation between adjacent optical components, such as... Figure 2 As shown, the aforementioned light shield 211 is provided on the front half shell 21.

[0034] This embodiment optimizes the anti-crosstalk structure. In addition to providing the strip-shaped opening 131 and the light-shielding plate 211 on the circuit board 13, light-blocking ribs can be added inside the light-transmitting channel 210. These ribs are located between adjacent light-transmitting channels 210 to further block stray light. Furthermore, the surface of the surface-mount components of the infrared emitter 11 and infrared receiver 12 can be coated with black light-shielding adhesive to reduce light reflection from the components themselves. The substrate of the circuit board 13 can be made of opaque FR-4 material, and the inner wall of the light-transmitting hole 130 is matte-finished to reduce light scattering.

[0035] In other embodiments, the hand gesture sensing module 1 may include three infrared transmitters 11 and two infrared receivers 12, wherein the infrared transmitters 11 and infrared receivers 12 are arranged alternately adjacent to each other, forming a linear array of "transmitter-receiver-transmitter-receiver-transmitter". Each infrared receiver 12 is configured to share with the two adjacent infrared transmitters 11, that is, each infrared receiver 12 is responsible for receiving the reflected signals from the two infrared transmitters 11 to its left and right. The controller controls all infrared transmitters 11 to operate in a staggered manner (e.g., time-sharing and alternating transmission), thereby enabling the recognition of more complex gestures (such as multi-directional waving or pausing gestures). This layout expands the functionality of gesture recognition while maintaining compactness.

[0036] This embodiment provides a range hood using the aforementioned hand gesture sensing device. The range hood includes a housing and a hand gesture sensing device located on the front of the housing. The hand gesture sensing device is fixed to the housing by a mounting plate 3, which has a front-opening storage groove. The fixing shell 2 of the hand gesture sensing device is fully embedded in the storage groove and secured with screws. The hand gesture sensing device is positioned near the control panel of the range hood for easy operation by the user's hand gesture. The controller is connected to the main control board of the range hood and generates control commands (such as turning on, turning off, and adjusting the airflow) based on the recognized gesture. Because the hand gesture sensing module 1 is compactly integrated, only a small window is needed on the housing to correspond to the light-shielding sleeve 4, significantly reducing the need for openings in the metal panel and improving both aesthetics and strength.

[0037] The misaligned transmission control method of the hand gesture sensing device in this embodiment is as follows:

[0038] The controller cyclically controls the operation of two infrared transmitters 11 in fixed time slices: in the first time slice, the first infrared transmitter 11 is activated to emit infrared pulses, and the second infrared transmitter 11 is deactivated; in the second time slice, the second infrared transmitter 11 is activated to emit infrared pulses, and the first infrared transmitter 11 is deactivated. The infrared receiver 12 synchronously detects the intensity of the reflected signal in each time slice and converts the analog signal into a digital signal for the controller to analyze. The controller determines the direction of the gesture and other hand gestures by comparing the relevant signal parameters and timing of adjacent time slices. Specifically, the two infrared transmitters 11 (i.e., reflector 1 and transmitter 2) emit infrared signals at a certain frequency, h, with a duty cycle of a; transmitters 1 and 2 emit at staggered intervals, thus detecting a wave of the hand. The waveform received by the phototransistor generally exhibits a structure similar to a normal distribution, as shown in the figure below.

[0039]

[0040] The controller's program can be used to characterize the waving speed by setting a threshold for the signal time width 'a';

[0041] The signal amplitude b represents the distance between the wave and the gesture window. The closer the distance, the larger the signal amplitude. By setting a signal amplitude threshold, the wave distance can be set.

[0042] The number of signal pulses, c, represents the waving speed and the time spent in front of the window.

[0043] Therefore, the rising slope d1 and falling slope d2 in the above diagram can characterize the waving speed;

[0044] The controller describes the waving characteristic waveform by setting the above parameter thresholds, distinguishes it from other irregular interference waveforms, identifies the correct waving waveform, and filters out interference waveforms.

[0045] The hand gesture sensing device for kitchen appliances in this embodiment effectively solves the processing complexity and aesthetic problems caused by the need for multiple independent components for multi-gesture recognition by arranging at least two infrared transmitters 11 adjacently and sharing a central infrared receiver 12 to form a compact hand gesture sensing module 1. Because the transmitter and receiver are integrated close together, the number of openings on the product panel is significantly reduced, lowering the processing difficulty and cost of the metal panel, while enhancing panel strength and overall aesthetics. Furthermore, through staggered transmission (i.e., alternating infrared signal transmission), the infrared receiver 12 can capture signal changes at different points in time during the hand gesture, forming a waveform similar to a normal distribution, thereby accurately identifying the gesture trajectory and direction, ensuring the accuracy and reliability of gesture recognition. This design improves the adaptability of kitchen appliance structures, simplifies assembly processes, and increases production efficiency and industrial design flexibility.

[0046] The range hood (including fan on / off, airflow adjustment, and self-cleaning program control) can be controlled not only through the gesture recognition scheme mentioned above, but also through a voice module. This module is equipped with a controller, a voice receiving module, and a voice parsing module. The voice receiving module receives user commands, which are then parsed by the voice parsing module. Based on the parsed commands, the controller controls the range hood to perform the corresponding operations, thereby achieving intelligent control of the range hood and improving the user experience.

[0047] The kitchen appliances in this embodiment are not limited to range hoods; they can also be integrated cooktops, dishwashers, steam ovens, and other products.

Claims

1. A gesture sensing device for kitchen appliances, comprising a gesture sensing module (1) and a controller, wherein the gesture sensing module (1) comprises an infrared transmitter (11) and an infrared receiver (12), and both the infrared transmitter (11) and the infrared receiver (12) are electrically connected to the controller, characterized in that: The hand gesture sensing module (1) has at least two infrared transmitters (11) arranged adjacent to each other, and an infrared receiver (12) is provided between the two adjacent infrared transmitters (11). The two adjacent infrared transmitters (11) and the infrared receiver (12) located between them together constitute a hand gesture sensing module (1). The hand gesture sensing module (1) is configured such that the two adjacent infrared transmitters (11) share an infrared receiver (12), and the two adjacent infrared transmitters (11) emit infrared signals outward in a staggered manner.

2. The gesture sensing device for kitchen appliances according to claim 1, characterized in that: The distances between two adjacent infrared transmitters (11) and the infrared receiver (12) located between them are equal.

3. The gesture sensing device for kitchen appliances according to claim 2, characterized in that: The infrared receiver (12) is a phototransistor.

4. The gesture sensing device for kitchen appliances according to any one of claims 1 to 3, characterized in that: It also includes a circuit board (13), and each of the infrared emitters (11) and infrared receivers (12) is mounted on the back of the circuit board (13) in a patch-connected manner. The circuit board (13) is also provided with a light-transmitting hole (130) that extends from its front to its back. The sensing end of each of the infrared emitters (11) and the sensing end of the infrared receivers (12) are located in the corresponding light-transmitting hole (130) on the circuit board (13).

5. The gesture sensing device for kitchen appliances according to claim 4, characterized in that: It also includes a fixed shell (2), and the hand gesture sensing module (1) and controller are all located in the fixed shell (2). The fixed shell (2) includes a front half shell (21) and a rear half shell (22) that are fastened together. A light-transmitting channel (210) extending from front to back is constructed on the front half shell (21). The light-transmitting channel (210) is opposite to the light-transmitting hole (130) on the circuit board (13). The rear port of the light-transmitting hole (130) is connected to the light-transmitting hole (130) on the circuit board (13). A light-shielding member (41) with a semi-transparent black material is also provided at the front port of the light-transmitting hole (130).

6. The gesture sensing device for kitchen appliances according to claim 5, characterized in that: The visible light transmittance of the light-shielding element (41) is less than 20%, and the infrared light transmittance is greater than or equal to 70%.

7. The gesture sensing device for kitchen appliances according to claim 5, characterized in that: Each light-transmitting hole (130) on the front half shell (21) corresponding to a wave sensing module (1) protrudes forward relative to the main body of the front half shell (21). The front part of the front half shell (21) is also provided with a light-shielding sleeve (4) sleeved on the protruding part of each light-transmitting hole (130). The light-shielding member (41) is provided on the light-shielding sleeve (4) at least in the area opposite to the front port of the light-transmitting hole (130).

8. The gesture sensing device for kitchen appliances according to claim 5, characterized in that: The circuit board (13) is provided with a strip opening (131) between adjacent infrared transmitters (11) and infrared receivers (12) for isolating the two. A light shield (211) that can be embedded in the strip opening (131) is provided on the front half shell (21) or the rear half shell (22).

9. The gesture sensing device for kitchen appliances according to claim 8, characterized in that: The edge of the strip-shaped opening (131) is also provided with a light-shielding layer.

10. A range hood, comprising a housing and a gesture sensing device disposed on the housing, characterized in that: The hand gesture sensing device is the hand gesture sensing device for kitchen appliances according to any one of claims 1 to 9.

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