Patent Publication Number: US-2020302130-A1

Title: Power-saving card reader device and access control system using the device

Description:
FIELD 
     The subject matter herein generally relates to efficient power distribution. 
     BACKGROUND 
     A traditional access control system can adopt radio frequency identification (RFID) technology. An identifier in an access card is energized and responds to an energy input by broadcasting, a broadcast response is received and demodulated by a card reader, and the legality and validity of the access card are thereby determined. Such traditional access control system needs to continuously supply power to the card reader for instant sensor recognition of the access card. The continuous power supply from the traditional access control system to the card reader can lead to a large power consumption and an additional cost. 
     Therefore, there is a room for improvement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       Implementations of the present disclosure will now be described, by way of embodiments, with reference to the attached figure. 
         FIG. 1  is a diagram of an embodiment of an access control system utilizing a card reader. 
     
    
    
     DETAILED DESCRIPTION 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. Additionally, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein. 
     Several definitions that apply throughout this disclosure will now be presented. 
     The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series, and the like. 
       FIG. 1  illustrates an access control system  1  in accordance with an embodiment of the present disclosure. 
     The access control system  1  can include a card reader device  100  and an access card  200 . In the embodiment, the access card  200  has an identifier. 
     In at least one embodiment, the identifier in the access card  200  may be a radio frequency identification (RFID) technology. The card reader device  100  transmits a radio frequency (RF) signal, receives and demodulates a response of the identifier of the access card  200 , and determines the legality and validity of the access card  200 . 
     In at least one embodiment, the access control system  1  can be applied to a channel port. The card reader device  100  can be mounted on a door or a wall of a passage opening. The access card  200  is carried by a user. The card reader device  100  is configured to determine the legality and validity of the access card  200 , and determine whether to open the channel port to allow access. 
     In at least one embodiment, the card reader device  100  includes a power source module  10 , a switch module  20 , a wireless tag reader  30 , an antenna module  40 , a sensor  50 , and a processor  60 . In one embodiment, the wireless tag reader  30  may be an RFID reader. 
     In at least one embodiment, the power source module  10  is electrically connected to the wireless tag reader  30  through the switch module  20 . The wireless tag reader  30  is electrically connected to the antenna module  40 . 
     When the switch module  20  is turned on, the power source module  10  is connected to the wireless tag reader  30  and the antenna module  40  to supply power to the card reader device  100 . When the switch module  20  is turned off, the power source module  10  is disconnected from the wireless tag reader  30  and the antenna module  40 , and the card reader device  100  receives no power. 
     In at least one embodiment, the power source module  10  is electrically connected to an alternating current (AC) power supply (not shown), to provide power requirements for the operation of the card reader device  100 . 
     In another embodiment, the power source module  10  is equipped with a battery or a super capacitor, to provide power requirements for the operation of the card reader device  100 . 
     In at least one embodiment, the power source module  10  can be a power output device in any form to provide a stable power for the operation of the card reader device  100 . 
     In at least one embodiment, the switch module  20  can be a digital switch. The switch module  20  is turned off by a logic-low voltage. The switch module  20  is turned on by a logic-high voltage. 
     In at least one embodiment, when the wireless tag reader  30  receives power, the wireless tag reader  30  transmits an RF signal through the antenna module  40 , to drive the access card  200 . The wireless tag reader  30  further receives the response of the identifier, transmitted by the access card  200 , and the antenna module  40  receives the response and demodulates the response. 
     In at least one embodiment, the antenna module  40  has a radiation range. When the access card  200  enters the radiation range, a radio frequency signal is transmitted by the antenna module  40 , and the antenna module  40  can receive the response from the identifier of the access card  200 . Within the radiation range, the card reader device  100  can establish a wireless communication connection with the access card  200 . 
     In another embodiment, the wireless tag reader  30  can be other types of wireless tag readers. The wireless tag reader  30  can read the identifier of the access card  200  through protocols such as WI-FI or BLUETOOTH. 
     In at least one embodiment, the sensor  50  is configured to detect a magnetic object (such as a magnetic component) and thereby transmit a detection signal. 
     In at least one embodiment, the sensor  50  can be, but is not limited to, a Hall sensor. When the magnetic object is close to the sensor  50 , the sensor  50  detects a change in a magnetic field. An increase in magnetic flux is detected by the sensor  50 , and the detection signal is output by the sensor  50 . In the embodiment, the detection signal can be a logic-high voltage signal. 
     In at least one embodiment, the sensor  50  has a detection range. When the magnetic object enters the detection range, the sensor  50  detects the change in the magnetic field. 
     In at least one embodiment, the switch module  20  and the processor  60  are electrically connected to the sensor  50 , and the sensor  50  outputs the detection signal to the switch module  20  and the processor  60 . 
     In at least one embodiment, the processor  60  is electrically connected to the wireless tag reader  30 . The processor  60  is configured to determine the legality and validity of the identifier response of the access card  200  received by the wireless tag reader  30 . The card reader device  100  can store a default value. 
     In at least one embodiment, the processor  60  can be a microcontroller unit (MCU). 
     The processor  60  compares the identifier response of the access card  200  with the default value stored in the card reader device  100 . When the identifier response of the access card  200  matches the default value stored in the card reader device  100 , the processor  60  can determine that the access card  200  is legal. 
     When the processor  60  determines that the access card  200  is legal, the processor  60  can confirm the identity of the access card  200  to further control the action of the channel port, such as opening the door of the channel port. 
     In at least one embodiment, the processor  60  has an enable terminal (not shown). When the enable terminal of the processor  60  receives a logic-high voltage, the processor  60  is activated, otherwise, the processor  60  is in a sleep state. 
     In at least one embodiment, the access card  200  can include a storage module  220 , a drive module  240 , and a magnetic object  260 . 
     The storage module  220  stores the response of the identifier of the access card  200 . In at least one embodiment, the identifier response of the access card  200  is unique and identifies the access card  200 . 
     The drive module  240  is configured to be driven when receiving the RF signal transmitted by the card reader device  100 , and transmits the response of the identifier of the access card  200  to the card reader device  100 . 
     The magnetic object  260  can be disposed in a housing (not shown) of the access card  200 . In another embodiment, the magnetic object  260  can also be exposed outside the housing of the access card  200 . 
     In at least one embodiment, the switch module  20  is turned off if the enable terminal of the processor  60  is not receiving the logic-high voltage and the power source module  10  is disconnected from the wireless tag reader  30 . When power is not supplied to the card reader device  100 , the card reader device  100  achieves power saving state. 
     In at least one embodiment, when a user uses the access card  200  for identity verification, the access card  200  is physically close to the card reader device  100 , and the magnetic object  260  of the access card  200  enters the detection range of the sensor  50  of the card reader device  100 . The sensor  50  detects the change in the magnetic field. When the detected magnetic flux increases, the detection signal is output to the switch module  20  and the processor  60 . In the embodiment, the detection signal is a logic-high voltage signal. 
     The switch module  20  is turned on according to the logic-high voltage signal. The power source module  10  supplies power to the wireless tag reader  30 , and the wireless tag reader  30  transmits the RF signal through the antenna module  40 . The drive module  240  of the access card  200  receives the RF signal and is driven to respond, broadcasting the response to the card reader device  100 . The wireless tag reader  30  receives the response of the access card  200  through the antenna module  40 , demodulates the same, and transmits result of demodulation to the processor  60 . The processor  60  is activated when the processor  60  receives the logic-high voltage signal. The processor  60  compares the response of identifier of the access card  200  with the default value stored in the card reader device  100  to determine the legality and validity of the access card  200 . 
     When the card reader device  100  is not in use, the sensor  50  does not detect any change in the magnetic field and the power source module  10  does not supply power to the wireless tag reader  30 . The card reader device  100  achieves a power saving state. When the access card  200  is brought close to the card reader device  100 , the sensor  50  detects the change in the magnetic field and controls the power source module  10  to supply power to the wireless tag reader  30 . The card reader device  100  can authenticate the access card  200 . 
     Therefore, although fully operational, the card reader device  100  can effectively save energy, reduce costs, and meet the needs of green environmental protection. 
     Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the exemplary embodiments described above may be modified within the scope of the claims.