Patent Publication Number: US-8111135-B2

Title: USB fingerprint scanner with touch sensor

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
     This application claims priority from Hong Kong short-term patent application no. 09100803.8 filed Jan. 23, 2009, the entire content of which is hereby incorporated by reference. 
     FIELD OF PATENT APPLICATION 
     The present patent application relates generally to a fingerprint scanning device, and particularly to a universal serial bus (USB) fingerprint scanner with a touch sensor. 
     BACKGROUND 
     As science and technology develops, more and more high technology products are used in consumer&#39;s daily life. A fingerprint scanning device is one of the high technology products that are widely used in areas such as electronic door entrances, ID verification in computing systems and banking systems, etc. However, existing fingerprint scanning devices do not provide users with any indications as to whether the fingerprint scanning is successful or not, or what is the operation status of the fingerprint scanning devices. Therefore, there is a need to produce an improved fingerprint scanning device that is able to indicate the operation status of the fingerprint scanning device and indicate whether the fingerprint scanning is successful or not during the fingerprint scanning process. 
     The above description of the background is provided to aid in understanding a USB fingerprint scanner, but is not admitted to describe or constitute pertinent prior art to the USB fingerprint scanner disclosed in the present patent application, or consider any information as material to the patentability of the claims of the present patent application. 
     SUMMARY 
     A fingerprint scanner is provided. The fingerprint scanner includes a control module for detecting and controlling the transmission of signals, an electrical connector coupled to the control module for connecting the fingerprint scanner to a periphery device, a plurality of light emitting diode (LED) indicators coupled to the control module to indicate operation status of the fingerprint scanner, and a fingerprint scanning module. The fingerprint scanning module is coupled to the control module to detect fingerprints and sense touches, and send fingerprint signals and touch signals to the control module. The fingerprint scanning module includes a touch sensor for sensing different touches that represent different command signals. 
     The fingerprint scanning module may include a fingerprint sensor in the form of a flexible circuit. 
     The fingerprint scanning module may include a radio frequency fingerprint scanning module. 
     The plurality of LED indicators may have different sizes arranged in a series according to their sizes. 
     The plurality of LED indicators may be disposed separately from the flexible circuit. 
     The plurality of LED indicators may have different colors to indicate different scanning status of the fingerprint scanner. 
     The fingerprint scanner may further include an audio indicator to indicate the scanning status of the fingerprint scanner. The audio indicator may be a speaker or a buzzer. 
     The electrical connector may be a USB connector. 
     The fingerprint scanning module may adopt vertical or horizontal fingerprint scanning. 
     The fingerprint scanning module may adopt annular fingerprint scanning. The annular fingerprint scanning is in a clockwise or anticlockwise direction with finger movement through more than 20 degrees. 
     The fingerprint scanning module may adopt a combination of linear and annular fingerprint scanning. 
     The control module may receive fingerprint scanning signals from the fingerprint scanning module and send commands that correspond to the fingerprint scanning signals to a host computer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Specific embodiments of the USB fingerprint scanner disclosed in the present patent application will now be described by way of example with reference to the accompanying drawings wherein: 
         FIG. 1  is a block diagram of the USB fingerprint scanner according to an embodiment disclosed in the present patent application; 
         FIG. 2  is a top plan view of the USB fingerprint scanner according to an embodiment disclosed in the present patent application; 
         FIG. 3  is a circuit diagram of the USB fingerprint scanner; 
         FIG. 4  is a circuit diagram of a fingerprint sensor of the USB fingerprint scanner; 
         FIG. 5  is a circuit diagram of a USB interface of the USB fingerprint scanner; and 
         FIG. 6  is a circuit diagram of an audio indicator of the USB fingerprint scanner. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to a preferred embodiment of the USB fingerprint scanner disclosed in the present patent application, examples of which are also provided in the following description. Exemplary embodiments of the USB fingerprint scanner disclosed in the present patent application are described in detail, although it will be apparent to those skilled in the relevant art that some features that are not particularly important to an understanding of the USB fingerprint scanner may not be shown for the sake of clarity. 
     Furthermore, it should be understood that the USB fingerprint scanner disclosed in the present patent application is not limited to the precise embodiments described below and that various changes and modifications thereof may be effected by one skilled in the art without departing from the spirit or scope of the appended claims. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims. 
     It should be noted that throughout the specification and claims herein, when one element is said to be “coupled” or “connected” to another, this does not necessarily mean that one element is fastened, secured, or otherwise attached to another element. Instead, the term “coupled” or “connected” means that one element is either connected directly or indirectly to another element, or is in mechanical or electrical communication with another element. 
       FIG. 1  shows a block diagram of the USB fingerprint scanner according to an embodiment disclosed in the present patent application. The USB fingerprint scanner may include a housing  100 , a control module  101  mounted within the housing  100 , a fingerprint scanning module  102  coupled to the control module  101 , a USB plug or connector  103  coupled to the control module  101 , one or more LED indicators  104  coupled to the control module  101  to indicate the scanning status of the fingerprint scanner, and an audio indicator  105  to indicate the scanning status of the fingerprint scanner. 
     The housing  100 , as shown in  FIG. 2 , may be shaped and sized to accommodate therein the control module  101 , the fingerprint scanning module  102  and the USB connector  103 . The housing  100  may be made of plastic or any suitable material. 
     The control module  101  may be in the form of a board with electrical circuits formed thereon. The control module  101  can be fixedly mounted inside the housing  100 . The control module  101  includes circuits for detecting signals and controlling the transmission of the detected signals. For example, the control module  101  can receive and process the fingerprint signals transmitting from the fingerprint scanning module  102  and send the processed fingerprint signals through the USB connector  103  to a periphery device such as a host computer or an electronic door entrance. The control module  101  may also receive signals from the fingerprint scanning module  101  and transmit signals to the LED indicators  104  to indicate the operation status of the fingerprint scanner  102  during a fingerprint scanning process. A circuit diagram of the USB fingerprint scanner of the present patent application is shown in  FIG. 3 . 
     The fingerprint scanning module  102  may include a fingerprint sensor for detecting fingerprints and transmitting fingerprint signals to the control module  101 . The fingerprint scanning module  102  may be in the form of any existing fingerprint scanning module. For example, the fingerprint scanning module  102  can be in the form of a radio frequency fingerprint scanning module. The fingerprint scanning module  102  may use a flexible circuit as a sensor for detecting the fingerprints. A circuit diagram of a fingerprint sensor of the fingerprint scanning module  102  is shown in  FIG. 4 . The size of the fingerprint scanning module  102  should be small enough to be accommodated within the housing  10  rendering the USB fingerprint scanner of the present patent application small, lightweight, compact and portable. 
     The fingerprint scanning module  102  may have a touch sensor for sensing a touch by a user and sending a touch signal to the control module  101 . For example, when a user touches a surface of the sensor by a finger, the sensor of the fingerprint scanning module  102  can sense the touch and send a corresponding signal/command to a host computer. Different touches can be defined to represent different command signals. For example, a continuous and quick touch on the surface of the sensor may be defined as a signal to turn on the host computer, and two continuous and quick touches on the surface of the sensor may be defined as a signal to turn on the display of the host computer, and so on. 
     The fingerprint scanning module  102  may adopt horizontal or vertical fingerprint scanning. For example, when a user places his or her finger on the surface of the sensor of the fingerprint scanning module  102 , the fingerprint scanning module  102  may carry out fingerprint scanning horizontally from left to right, or vertically from top to bottom, or a combination thereof at the same time. The fingerprint scanning module  102  may adopt annular scanning in a clockwise or anticlockwise direction. This can be achieved by moving a finger on the surface of the sensor clockwise or anticlockwise through a certain degree, such as more than 20 degrees. The fingerprint scanning module  102  may also adopt a combination of linear and annular fingerprint scanning. 
     The fingerprint scanner in the present patent application can also detect finger swiping direction by the following steps: 
     1. Capture a fingerprint image by using a line sensor that can sense from the moment a finger touches the sensor to the moment the finger leaves the sensor. The captured image will therefore contain a fingerprint with information on time (i.e. finger motion). 
     2. Determine the gradient (slope) of the line pattern of the image by (i) applying an edge detection algorithm on the gray scale image, and (ii) determining the gradient of each line (edge). 
     3. Determine the finger swiping direction based on the line pattern. 
     The fingerprint scanner of the present patent application may contain very small RF transmitters and a RF receiver. When a user touches the sensor, it will affect the impedance in the sensor. After detecting the change of impedance, the sensor can recognize that a user is touching the sensor of the fingerprint scanner. 
     The USB connector  103  is coupled to the control module  101  and provides an interface between the fingerprint scanner and the periphery devices such as a host computer. A circuit diagram of the USB interface of the fingerprint scanner of the present patent application is shown in  FIG. 5 . It is understood by one skilled in the art that any other forms of connector, such as an IEEE1394 connector, or any wireless communication such as infrared or Bluetooth may be employed. 
     The LED indicators  104  are employed to indicate the operation status of the USB fingerprint scanner. According to the illustrated embodiment in  FIG. 2 , a plurality of LED indicators  104  is provided on an upper surface of the housing  100  of the USB fingerprint scanner. The plurality of LED indicators  104  can be of different shapes, sizes or colors to indicate to the user different operating conditions of the USB fingerprint scanner during a fingerprint scanning process. 
     As shown in the illustrated embodiment in  FIG. 2 , there are four oblong-shaped LED indicators  104  with elongated sides extending transversely across the housing  100 . It can be seen that the four LED indicators  104  can have similar shapes but different sizes and are arranged in a series on the housing  100  according to their sizes. The four LED indicators  104  can be used to indicate the operation status of the fingerprint scanner. For example, one of the LED indicators  104  may be lit when fingerprint scanning is not successful and two of the LED indicators  104  may be lit when fingerprint scanning is successful. One or more of the LED indicators  104  may be flashing to indicate that the fingerprint scanning is in progress. The lights of all of the LED indicators  104  may be switched off to indicate the completion of the fingerprint scanning process. 
     The LED indicators  104  may be in different colors to indicate different operating conditions of the fingerprint scanner. For example, the LED indicators  104  may be lit in green color when the fingerprint scanning is successful and in red color when the fingerprint scanning is not successful. 
     In addition to the four LED indicators  104 , there is one LED indicator in the shape of an arrow head or a triangular bracket pointing at one end of the housing  100 . This LED indicator can be used to indicate the operating instructions or operating position on the fingerprint scanner. For example, the LED indicator can be lit in green color to indicate that the fingerprint scanner is in its “on” position ready for fingerprint scanning, or the LED indicator  104  can be used to point at a position at the end of the housing  100  where a user can access a fingerprint scanning surface of the fingerprint scanner. The user can then place his/her finger on the fingerprint scanning surface to start the fingerprint scanning process. 
     The fingerprint scanner may also include an audio indicator  105 . The audio indicator  105  may be connected to the control module  101  to indicate the scanning status of the fingerprint scanning device. The audio indicator  105  may be in the form of a speaker or a buzzer so long as it can generate an audible sound. For example, a short audible sound may represent successful scanning and a long audible sound may represent a scanning failure.  FIG. 6  is a circuit diagram of the audio indicator  105  of the USB fingerprint scanner. 
     While the USB fingerprint scanner disclosed in the present patent application has been shown and described with particular references to a number of preferred embodiments thereof, it should be noted that various other changes or modifications may be made without departing from the scope of the appending claims.