TWI399542B - Motion sensor and electronic device with motion sensor - Google Patents

Description

Motion sensor and electronic device having the same

The present invention relates to a motion sensor and an electronic device having the same.

Nowadays, more and more businesses realize that the characteristics and functions of supporting sports are effective ways to make their products unique. It changes the way consumers interact with their electronic products, and the motion sensor is the key. Elements. Apple's iPhone realizes the vertical and horizontal conversion of the view through motion sensors. The Nintendo Wii game console uses motion sensors to control game movements through motion input, making motion sensors widely used in consumer electronics. Opened a huge consumer market for motion sensors. In addition to mobile phones, current motion sensors are said to support hundreds of applications and products, including sports aids, digital cameras and camcorders, and notebook active hard drive protection.

At present, typical motion sensors generally include piezoresistive motion sensors, capacitive motion sensors and piezoelectric motion sensors. Among them, piezoresistive motion sensors are made by the piezoresistive effect of single crystal germanium materials, which are greatly affected by temperature and process. It is more complicated and costly; the capacitive motion sensor uses a capacitor with variable parameters as the force sensitive component, and its output has nonlinearity. The parasitic capacitance and distributed capacitance have great influence on sensitivity and measurement accuracy, and the connection circuit is complicated.

In view of the above problems, the present invention provides a novel motion sensing The motion sensor includes a cavity, a plurality of pressure sensing units and a weight. The plurality of pressure sensing units and the weights are respectively received in the cavity, and the weights are placed in a central area of the cavity, each of the The pressure sensing unit has one end in contact with the weight and the other end is fixed on the side wall of the cavity. Each pressure sensing unit comprises: a planar element, a surface of the planar element is in contact with the weight, and the other The surface is provided with a conductive chute having a uniform resistance value; the elastic support frame is made of a conductive material, and includes a fixed end fixedly connected to the side wall of the cavity and a free end slidable in the conductive chute; Wherein, when the motion sensor moves in a certain direction, the weight compresses the pressure sensing unit in the opposite direction due to the inertia, so that the free end of the elastic support frame in the pressure sensing unit in the direction moves relatively, This causes a change in the electrical resistance between the fixed ends of the elastic support to reflect the direction of the motion.

An electronic device includes a motion sensor and a processing unit. The motion sensor includes a cavity, a plurality of pressure sensing units, and a weight. The plurality of pressure sensing units and the weights are received in the cavity. The inner portion of the pressure sensing unit is placed in contact with the weight and the other end is fixed to the side wall of the cavity. Each of the pressure sensing units includes a planar element and an elastic support frame, the surface element having a surface in contact with the weight, and the other surface being provided with a conductive chute having a uniform resistance value. The elastic support frame is made of a conductive material, includes a fixed end fixedly connected to the side wall of the cavity, and is slidable in the conductive The free end of the slide in the slot. When the motion sensor moves in a certain direction, the weight compresses the pressure sensing unit in the opposite direction due to the inertia, so that the free end of the elastic support frame in the pressure sensing unit in the direction moves relatively, resulting in elasticity. The resistance between the fixed ends of the support frame changes. The processing unit is electrically connected to the motion sensor for providing a fixed voltage between the fixed ends of the elastic support frame, and sensing the change of the current between the fixed ends of the elastic support frames in each direction to sense the resistance change, thereby judging The current direction of motion and the corresponding action is performed according to the direction of motion.

The invention has simple structure, small influence by environmental factors, low power consumption and low cost.

Referring to FIG. 1, the motion sensor 1 includes a weight 2, a plurality of pressure sensing units 3, and a cavity 4. The weight 2 and the plurality of pressure sensing units 3 are respectively received in the cavity 4. In the embodiment, the cavity 4 is a square receiving cavity, and the number of the plurality of pressure sensing units 3 is four. The weight 2 is a rectangular parallelepiped structure, the four sides of the weight 2 are parallel to the four side walls of the cavity 4, and one end of each pressure sensing unit 3 is in contact with one side of the weight 2, and the other end is fixedly connected to the cavity. On the inner side wall of the body 4.

Please refer to Figure 2 and Figure 3 together. Each of the pressure sensing units 3 includes a planar member 31 and an elastic support frame 32.

The planar element 31 is a square planar element made of an insulating material which is slightly smaller than the side walls of the cavity, one surface of which is parallel to and in contact with the side of the weight 2. On the side of the planar element 31 that is not in contact with the weight 2, two mutually intersecting conductive chutes 311 having a uniform resistance value are disposed. The conductive chute 311 is a semi-arc groove structure recessed into the interior of the planar member 31. The length of the groove is slightly smaller than the diagonal length of the planar member 31, so that both ends of the conductive chute form a closed structure.

The elastic support frame 32 is made of a conductive material and includes four bracket arms 33, 34, 35, 36, each of which is an L-shaped structure, wherein the bracket arm 33 includes a fixed end 331, a curved portion 332, and a free end 333. The bracket arm 34 includes a fixed end 341, a curved portion 342 and a free end 343. The bracket arm 35 includes a fixed end 351, a curved portion 352 and a free end 353. The bracket arm 36 includes a fixed end 361, a curved portion 362 and a free end 363, respectively. The free end and the fixed end of each of the bracket arms are connected by the curved portion, and the free ends are all an arc-shaped raised end. The fixed ends 331, 341, 351, and 361 are fixedly connected to the sidewalls of the cavity 4, and the free ends 343 and 363 of the bracket arms 34 and 36 are located in the same conductive slot 311 to be in contact with the conductive slot 311. The free ends 332 and 352 of the bracket arms 33 and 35 are located in the other conductive slot 311 and are in contact with the conductive slot 311 and can slide in the conductive slot 311.

When the motion sensor 1 moves in a certain direction, the weight 2 presses the elastic support frame 32 of the pressure sensing unit 3 in the opposite direction due to inertia, resulting in compression deformation of the elastic support frame 32 in the direction. The bracket arms 33, 34, 35, 36 are bent along the respective bent portions, so that the free ends 343 and 363, 333 and 353 slide toward each other in the conductive sliding slot 311, so that the free ends are located in the same conductive chute 311. The resistance between the fixed ends 341, 361 or the fixed ends 331, 351 is changed to reflect the direction of motion. This direction of motion is the opposite direction from the weight 2 to the direction of the elastic support frame 32 in which the deformation occurs.

The surface of the planar element 31 provided with the sliding slot is further provided with a plurality of guard columns 312 for protecting the pressure sensing unit 3 from excessive deformation of the elastic support frame 32.

In other embodiments, the motion sensor 1 can set the pressure sensing unit 3 in a corresponding direction as needed, for example, the motion sensor 1 can include six pressure sensings disposed in three coordinate directions of X, Y, and Z. Unit 3, thereby achieving motion sensing in three dimensions.

Referring to FIG. 4, in the embodiment, the cavity 4 of the motion sensor 1 is a regular cubic structure made of an insulating material, and four sidewalls of the cavity 4 are provided with four conductive through holes 41 for elastic support. The four fixed ends 331, 341, 351 and 361 of the frame 32 are embedded in the conductive through hole 41, so that the conductive through hole 41 is electrically connected to the fixed ends 331, 341, 351, 361 and fixes the elastic support frame 32; The cavity 4 further includes a conductive circuit 42 disposed along the outer surfaces of the four side walls, and a pad 43 disposed at the bottom of the cavity. The conductive circuit 42 is configured to connect the conductive via 41 to the pad 43 at the bottom of the cavity 4, the pad 43 is in one-to-one correspondence with the conductive via 41, and the motion sensor 1 is external to the pad 43 The circuits are connected, and the external circuit is electrically connected to the pressure sensing unit through the pad 43, the conductive circuit 42 and the conductive via 41 to form a loop.

In other embodiments, the surface of the cavity 4 can be provided with a conductive via 41 and a conductive circuit 42 in a corresponding direction as needed, for example, the cavity 4 can be six in three directions of the coordinate axes X, Y, and Z. Conductive through holes 41 and conduction circuits 42 are provided on the surface to realize motion detection in three dimensions.

As shown in FIG. 5, the motion sensor 1 is used in the schematic diagram of the electronic device 5. . The electronic device 5 includes a circuit board 51 carrying a processing unit (not shown), and the motion sensor 1 is carried on the circuit board 51. On the circuit board 51, the processing unit is connected to the motion sensor 1 through the pad 43 at the bottom of the cavity 4, so that the processing unit passes the pad 43, the conductive circuit 42 and the conductive via 41 and each pressure sensing. The fixed ends of the unit 3 are electrically connected, and the processing unit is configured to detect the resistance between the fixed ends of the two bracket arms located in the same conductive slot 311. The processing unit is connected to the fixed ends of the two bracket arms whose free ends are located in the same conductive slot 311 through the conductive circuit 42 of each side wall of the cavity 4, applying a constant potential difference U to the two fixed ends, and detecting Measuring the change of the current between the two fixed ends of the elastic support frame in each direction to sense the change of the resistance, and judging that the resistance of the two fixed ends of the elastic support frame changes in a certain direction, determining that the elastic support frame has occurred Elastic deformation. For the same pressure sensing unit 3, the processing unit only needs to detect the resistance between the two fixed ends of the two bracket arms of the same conductive slot 311. For example, the processing unit detects between the fixed ends 341 and 361. The resistor can be. Therefore, when the processing unit determines that the resistance between the two fixed ends of the elastic support frame changes, it is determined that the elastic support frame is deformed, and then the current moving direction of the electronic device 5 is determined to be the elastic support frame 32 that is deformed from the deformation. Go to the direction of the weight 2 and perform the corresponding action according to the direction of motion.

1‧‧‧ motion sensor

2‧‧‧ Heavyweight

3‧‧‧ Pressure sensing unit

4‧‧‧ cavity

5‧‧‧Electronic devices

31‧‧‧ planar components

311‧‧‧Electrical chute

312‧‧‧Guard column

32‧‧‧Flexible support frame

33, 34, 35, 36‧‧‧ bracket arms

331, 341, 351, 361‧‧ ‧ fixed end

332, 342, 352, 362‧‧‧ bending

333, 343, 353, 363‧‧ ‧ free end

41‧‧‧Electrical through holes

42‧‧‧ Conduction circuit

43‧‧‧ pads

51‧‧‧ boards

1 is a diagram showing the internal structure of a motion sensor according to an embodiment of the present invention.

2 is a structural view of a pressure sensing unit in the embodiment shown in FIG. 1.

3 is a schematic view of a bracket arm in the pressure sensing unit shown in FIG. 2.

Figure 4 is a structural view of a cavity in the embodiment shown in Figure 1.

Figure 5 is a schematic illustration of an electronic device having the motion sensor of Figure 1.

1‧‧‧ motion sensor

2‧‧‧ Heavyweight

3‧‧‧ Pressure sensing unit

4‧‧‧ cavity

Claims (10)

A motion sensor includes a weight, a plurality of pressure sensing units and a cavity, the plurality of pressure sensing units and the weights are housed in the cavity, and the weights are placed in a central area of the cavity, each of the The pressure sensing unit is in contact with the weight at one end and the other end is fixed to the sidewall of the cavity. The improvement is that each of the pressure sensing units comprises: a planar component, a surface of the planar component is in contact with the weight The other surface is provided with a conductive chute having a uniform resistance value; the elastic support frame is made of a conductive material, and includes a fixed end fixedly connected to the sidewall of the cavity and slidable in the conductive chute a free end; wherein, when the motion sensor moves in a certain direction, the weight compresses the pressure sensing unit in the opposite direction due to inertia, so that the free end of the elastic support frame in the pressure sensing unit in the direction occurs The relative motion causes a change in the electrical resistance between the fixed ends of the elastic support to reflect the direction of the motion. The motion sensor of claim 1, wherein the motion sensor cavity is a square accommodating cavity, and the number of the pressure sensing units is four, and the weight is a rectangular parallelepiped structure, and the weight is The four sides are parallel to the four side walls of the cavity, one end of each pressure sensing unit is in contact with one side of the weight, and the other end is fixedly connected to the inner side wall of the cavity. The motion sensor of claim 1, wherein the motion sensor comprises six pressure sensing units disposed around an inner surface of the square receiving cavity to achieve motion sensing in a three-dimensional direction. The motion sensor of claim 1, wherein the planar element is a square structure made of an insulating material, and one surface is provided with two conductive chutes that intersect each other. The motion sensor of claim 1, wherein the elastic support frame in each of the pressure sensing units comprises four bracket arms, the bracket arms are L-shaped structures, including a fixed end, and a bending And a free end, the free end is an arc-shaped raised end, and the two spaced apart bracket arms are located in the same conductive chute and can slide in the conductive chute. The motion sensor of claim 1, wherein the surface of the planar element with the conductive chute is further provided with a plurality of guard columns for protecting the pressure sensing unit. An electronic device includes a motion sensor and a processing unit. The motion sensor includes a cavity, a plurality of pressure sensing units, and a weight. The plurality of pressure sensing units and the weights are received in the cavity. The pressure sensing unit is disposed at a central portion of the cavity, and each of the pressure sensing units is in contact with the weight and the other end is fixed to the sidewall of the cavity. The improvement is that each of the pressure sensing units comprises: a planar component. One surface of the planar element is in contact with the weight, and the other surface is provided with a conductive chute having a uniform resistance value; and an elastic support frame made of a conductive material, including a fixed connection to the sidewall of the cavity And a free end slidable in the conductive chute; wherein, when the motion sensor moves in a certain direction, the weight compresses the pressure sensing unit in the opposite direction due to inertia, so that the direction is Relative movement of the free end of the elastic support frame in the pressure sensing unit causes a change in electrical resistance between the fixed ends of the elastic support frame; The processing unit is electrically connected to the motion sensor for providing a fixed voltage U between the fixed ends of the elastic support frame, and sensing the change of the current between the fixed ends of the elastic support frames in each direction to sense the resistance change, thereby judging The current direction of motion is derived and the corresponding action is performed according to the direction of motion. The electronic device of claim 7, wherein the cavity of the motion sensor is a square receiving cavity made of an insulating material, and the four sidewalls of the cavity are provided with a conductive through hole and a conductive circuit. The bottom of the cavity is provided with a pad corresponding to the conductive via hole, wherein the conductive via hole is used for fixing the elastic support frame and is electrically connected to the elastic support frame, and the conductive circuit connects the conductive via hole and the pad, the processing unit Located on the pad, the processing unit is connected to the fixed ends of the elastic support frame through the conductive circuit and the conductive through holes. The electronic device of claim 8, wherein when the motion sensor moves in a certain direction, the weight compresses a planar element in a direction opposite to the movement, while freeing the elastic support frame in the direction The end slides in the direction of the central region of the planar member along the conductive slot, so that the resistance between the free ends of the two elastic supports changes, so that the current detected by the processing unit changes. The electronic device of claim 7, wherein the processing unit detects that the current of the elastic support frame changes, determines that the elastic support frame is deformed, and determines that the movement direction of the electronic device is from the The deformed elastic support frame is oriented to the direction of the weight and the corresponding operation is performed according to the direction of movement.