TWI630561B - Dermatoglyph identification apparatus and identifying method thereof - Google Patents

Abstract

A skin pattern recognition device and a recognition method thereof. The texture recognition device includes a switching circuit, a signal source, and a plurality of sensors, and the signal source is selectively connected to the sensor through the impedance element. The switching circuit switches at least one sensor to the impedance element and connects the remaining sensors to the ground of the signal source. The texture recognition device recognizes the texture based on the sensing signal generated by the reference signal of the sensor response signal source connected to the impedance element.

Description

Skin pattern recognition device and identification method thereof

The present invention relates to an identification device, and more particularly to a skin texture recognition device and a method for identifying the same.

In today's electronic products, more and more devices have fingerprint recognition functions, such as mobile phones and tablets. Fingerprint recognition is becoming more and more widely used, for example, to identify a user. When detecting the change of the fingerprint bump, the capacitance value generated by the fingerprint is small, so when there is parasitic capacitance, or the human body does not share the fingerprint detection chip, the fingerprint capacitance value to be detected is serious. Attenuation, which makes fingerprinting difficult. In general, in order to solve this problem, a copper ring having the same ground potential as the internal fingerprint detecting chip can be disposed on the mobile phone, and when the user performs fingerprint recognition, the sensor and the copper ring are simultaneously contacted, and One end of the sensing capacitor has the same ground potential as the internal fingerprint detecting chip, so that the sensing capacitor has one end floating, thereby increasing the fingerprint recognition degree.

The invention provides a skin pattern recognition device and a recognition method thereof, and can accurately perform fingerprint identification without a copper ring.

The texture recognition device of the present invention includes a plurality of sensors, switching circuits, and signal sources. The sensor is used to detect the texture. The switching circuit is coupled to the ground of the sensor and the signal source. The signal source is coupled to the switching circuit through the impedance element, and the signal source generates a reference signal. The switching circuit switches at least one sensor connected to the impedance component, and switches the remaining sensors to the ground terminal, the at least one sensor reacts the reference signal to generate a sensing signal, and the skin pattern identifying device identifies the skin texture according to the sensing signal .

In an embodiment of the invention, the switching circuit alternately connects the sensor to the impedance element and switches the remaining sensors that are not switched to the impedance element to the ground.

In an embodiment of the invention, when the sensing object touches the plurality of sensors, the sensing capacitance corresponding to the at least one sensor transmits the sensing object corresponding to the remaining sensors. The capacitor is connected in series between the impedance element and the ground.

In an embodiment of the invention, the sensing object is a finger.

In an embodiment of the invention, the texture recognition device further includes a processing circuit coupled to the impedance component and the switching circuit to convert the sensing signal into sensing information.

In an embodiment of the invention, the processing circuit includes an amplifier and an analog digital conversion circuit. The amplifier is coupled to the impedance element to amplify the sensing signal. The analog digital conversion circuit is coupled to the amplifier and converts the amplified sensing signal into sensing information.

In an embodiment of the invention, each of the sensors includes a sensing electrode.

The invention also provides a skin pattern recognition method for a skin pattern recognition device, wherein the skin pattern recognition device comprises a signal source and a plurality of sensors, and the signal source is selectively connected to the sensor through the impedance element, and the skin pattern of the skin pattern recognition device The identification method includes the following steps. Switching at least one sensor to the impedance element. Switch the remaining sensors to the ground of the signal source. The skin texture is identified according to the sensing signal generated by the at least one sensor response reference signal.

In an embodiment of the invention, the dermatoglyph identification method of the dermatoglyph recognition apparatus includes alternately connecting the sensor to the impedance element.

In an embodiment of the invention, in the above, when the sensing object touches the plurality of sensors, the sensing capacitance corresponding to the at least one sensor passes through the sensing object and corresponds to the remaining sensors. The sensing capacitor is connected in series between the impedance element and the ground.

Based on the above, the texture recognition device of the embodiment of the present invention is connected to the impedance element by switching at least one sensor, and switches the remaining sensors to the ground end of the signal source, so that the sensor connected to the impedance element can be The reference signal provided by the reaction signal source generates a sensing signal on the impedance component, and the effect that the sensing capacitor and the signal source have a common ground can be achieved without the copper ring being disposed, and the fingerprint identification can be accurately performed.

The above described features and advantages of the invention will be apparent from the following description.

1 is a schematic view of a skin texture recognition device according to an embodiment of the present invention. Please refer to FIG. The smear identification device includes a plurality of sensors 102, a switching circuit 104, a signal source 106, and a processing circuit 110. The switching circuit 104 is coupled to each of the sensors 102 and the processing circuit 110, and the signal source 106 is coupled through the impedance element 108. The circuit 104 and the processing circuit 110, wherein the impedance element 108 can be, for example, a resistive element or an equivalent resistance of a circuit lead, but is not limited thereto.

The sensor 102 is configured to detect the fingerprint of the sensing object 112, such as a finger, for example, but not limited thereto, for example, detecting the skin texture of other parts, and the sensor 102 may include a sensing electrode, and the sensing The sensing electrodes of the device 102 can form a sensing array to define sensing regions for sensing the skin texture. Signal source 106 can generate a reference signal to cause sensor 102 to react to the reference signal to produce a sensed signal. When the sensing object 112 touches the sensor 102 to perform the texture recognition, the switching circuit 104 can switch the at least one sensor 102 to the impedance element 108 and switch the remaining sensors to the ground of the signal source 106. The ground terminal is connected to the ground voltage. In this case, the reference signal provided by the signal source 106 can be transmitted to the sensor 102 connected to the impedance element 108 through the impedance element 108, so that the sensor 102 connected to the impedance element 108 can generate a sensing signal in response to the reference signal. So that the texture recognition device can identify the texture according to the sensing signal. For example, the processing circuit 110 can convert the sensing signal into sensing information for skin texture recognition.

2 is a schematic diagram of an equivalent circuit of a skin texture recognition apparatus according to an embodiment of the present invention. Please refer to FIG. Further, when the sensing object 112 (for example, a finger) touches the sensor 102 to perform the texture recognition, the sensing capacitance Cf is generated between each of the sensors 102 and the sensing object 112. In the present embodiment, only one sensor 102 is switched and connected to the impedance element 108 by the switching circuit 104, and the remaining sensors 102 are switched to be connected to the ground of the signal source 106, wherein the grounding of the signal source 106 is switched. The sensing capacitance Cf corresponding to the sensor 102 of the terminal is a parallel connection relationship, which can be equivalent to the sensing capacitance Cf0 shown in FIG. 2, that is, the capacitance value of the sensing capacitor Cf0 is equal to being switched to be connected to The sum of the sense capacitors Cf corresponding to the sensors 102 of the ground of the signal source 106.

As shown in FIG. 2, the sense capacitance Cf corresponding to the sensor 102 that is switched to be connected to the impedance element 108 will pass through the sense corresponding to the sensor 102 that is switched to the ground of the signal source 106. The capacitance Cf0 is connected in series between the impedance element 108 and the ground. Since the capacitance of the sensing capacitor Cf0 is much larger than the capacitance of the sensing capacitor Cf, the capacitance of the series sensing capacitor Cf0 and the sensing capacitor Cf will be almost equal to The capacitance value of the capacitance Cf is sensed. As such, the sensed signal outputted at the common junction of the impedance element 108 and the sense capacitor Cf will only reflect the capacitance sensed by the sensor 102 that is switched to be connected to the impedance element 108, and due to FIG. 2 The sensing capacitor Cf0 and the sensing capacitor Cf are connected in series between the impedance element 108 and the ground, so that there is no problem that one end of the capacitor floats, and the sensor 102 that is switched and connected to the impedance element 108 can be accurately reflected. The sensed capacitance value. In addition, the processing circuit 110 can include, for example, an amplifier 202 and an analog-to-digital conversion circuit 204 in the present embodiment, wherein the amplifier 202 is coupled to the impedance element 108 and the analog-to-digital conversion circuit 204. The amplifier 202 can amplify the sensing signal, and the analog digital conversion circuit 204 converts the amplified sensing signal into sensing information for skin texture recognition.

The switching circuit 104 can switch the respective sensors 102 to the impedance element 108 in turn, and simultaneously switch the remaining sensors 102 that are not switched to the impedance element 108 to the ground to sequentially obtain the respective sensing. The sensing signal generated by the device 102 further obtains a change in the capacitance value of each position on the sensing array, and the skin texture characteristic of the sensing object can be accurately known.

FIG. 3 is a schematic flow chart of a method for identifying a dermatoglyph recognition apparatus according to an embodiment of the present invention. Please refer to FIG. 3. It can be seen from the above embodiments that the identification method of the texture recognition device may include the following steps. First, at least one sensor is switched to be connected to the impedance element to connect the signal source through the impedance element (step S302). Next, the remaining sensors are switched to be connected to the ground of the signal source (step S304). The skin texture is then identified based on the sensing signal generated by the sensor response reference signal connected to the impedance element (step S306). When the sensing object touches the sensor, the sensing capacitor corresponding to the sensor connected to the impedance component is connected to the sensing component and the grounding terminal through the sensing capacitor corresponding to the remaining sensor through the sensing object. Therefore, the sensing signal will only reflect the capacitance value sensed by the sensor switched to the impedance element, and there will be no problem that the capacitor is floating at one end, and the switched connection can be accurately reflected. The value of the capacitance sensed by the sensor to the impedance element. By sequentially connecting the sensor to the impedance element and simultaneously switching the remaining sensors not switched to the impedance element to the ground, the sensing generated by each sensor can be sequentially obtained. The signal, and thus the skin texture of the sensing object, is accurately known.

In summary, the texture recognition apparatus of the embodiment of the present invention connects to the impedance element by switching at least one sensor, and switches the remaining sensors to the ground end of the signal source to connect the impedance element. The detector can generate a sensing signal on the impedance element by reflecting a reference signal provided by the signal source. Thus, in the case where the copper ring is not disposed, the effect that the sensing capacitor and the signal source have a common ground can be achieved without the problem that the capacitor is floating at one end, so that the fingerprint can be accurately performed.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

102: sensor 104: switching circuit 106: signal source 108: impedance element 110: processing circuit 112: sensing object 202: amplifier 204: analog digital conversion circuit Cf, Cf0: sensing capacitance S302 ~ S306: skin texture recognition device Identification method steps

1 is a schematic diagram of a skin texture recognition device in accordance with an embodiment of the present invention. 2 is a schematic diagram of an equivalent circuit of a skin texture recognition device in accordance with an embodiment of the present invention. 3 is a schematic flow chart of a method for identifying a skin texture recognition device according to an embodiment of the invention.

Claims (10)

A skin pattern recognition device includes: a plurality of sensors for detecting a skin texture; a switching circuit coupled to the sensors, a signal source coupled to the switching circuit through an impedance component, the signal source The grounding end is coupled to the switching circuit, the signal source generates a reference signal, the switching circuit switches at least one sensor to the impedance component, and switches the remaining sensors to the ground of the signal source, the at least A sensor reflects the reference signal to generate a sensing signal, and the skin pattern identifying device identifies the skin texture according to the sensing signal. The skin texture recognition device of claim 1, wherein the switching circuit alternately switches the sensors to the impedance element and switches the remaining sensors that are not switched to the impedance element. Connect to the ground of this source. The skin texture recognition device of claim 1, wherein when a sensing object touches the sensors, the sensing capacitance corresponding to the at least one sensor passes through the sensing object and the remaining A sensing capacitor corresponding to the sensor is connected between the impedance element and a ground end of the signal source. The skin texture recognition device of claim 3, wherein the sensing object is a finger. The skin texture recognition device of claim 1, further comprising: a processing circuit coupled to the impedance component and the switching circuit to convert the sensing signal into a sensing information. The skin pattern recognition device of claim 5, wherein the processing circuit comprises: an amplifier coupled to the impedance element to amplify the sensing signal; and an analog-to-digital conversion circuit coupled to the amplifier and The amplified sensing signal is converted into the sensing information. The skin texture recognition device of claim 1, wherein each of the sensors comprises a sensing electrode. A skin pattern recognition method for a skin pattern recognition device, wherein the skin pattern recognition device comprises a signal source and a plurality of sensors, the signal source selectively connecting the sensors through an impedance element, the texture recognition device The method for identifying a skin pattern includes: switching at least one sensor to be connected to the impedance element; switching the remaining sensors to be connected to a ground end of the signal source; and generating a sense according to the at least one sensor reacting the reference signal The measurement signal identifies the texture. The method for identifying a texture of a texture recognition device according to claim 8 includes: switching the sensors to the impedance element in turn. The method for identifying a texture of a skin texture recognition device according to claim 8, wherein when a sensing object touches the sensors, the sensing capacitance corresponding to the at least one sensor transmits the feeling The sensing capacitor corresponding to the remaining sensors is connected in series between the impedance component and the ground of the signal source.