JP2003317040A - Power-saving RFID card reader / writer - Google Patents

Abstract

(57) [Summary] In a wireless card system, an interrogator does not always or intermittently transmit interrogation radio waves. Reduces power consumption and enables long-term use with small-capacity power supplies such as dry batteries. By using an object detection sensor provided at the center of the antenna of an interrogator or an operation sensor for detecting operation of a door opening / closing knob, transmission of an interrogation radio wave can be stopped when an interrogation is unnecessary. When the response radio wave from the transponder to the interrogation radio wave cannot be received, the interrogation radio wave is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interrogator for use in a wireless card system for entering / leaving a room and for confirming an individual.

[0002]

2. Description of the Related Art Conventionally, in a wireless card system, it is possible to reduce power consumption by providing an interrogator constantly transmitting an inquiry radio wave or intermittently transmitting an inquiry radio wave, regardless of whether or not a responder is provided. There is. Alternatively, a switch for starting the interrogator is separately provided, and by operating the switch, the interrogation radio wave is transmitted to reduce the power consumption.

[0003]

When the interrogator constantly or intermittently transmits the interrogation radio wave, the power consumption increases, and it is difficult to operate the interrogator for a long time using a low power capacity power supply device such as a dry battery. It was As measures against this, wiring for power supply is required and large-scale devices such as large-capacity batteries are required.This is a wireless card system for non-contact entry / exit control, but it is installed on the door or door lock. It was difficult to do so, or there was a contact-type start switch for starting the operation of the interrogator. Further, since the power consumption is large, it takes a lot of time to replace the battery. In addition, since the wireless card system has the property of maximizing communication performance in the positional relationship where the center of the interrogator antenna and the center of the responder antenna overlap on the same axis, it is necessary to position the interrogator antenna and responder individually. Or, it was necessary to transmit a high-power interrogation radio wave so that the communication characteristics can be expected even if the positional relationship is deviated. Furthermore, by providing a separate switch, it is necessary to add a dust-proof, water-proof and drip-proof structure to the switch section, which has caused weather resistance and aesthetic constraints.

[0004]

[Means for solving the problem] Normally, the transmission of the inquiry radio wave is stopped, and the inquiry radio wave is transmitted continuously or intermittently after the detection signal is obtained from the non-contact object detection sensor provided in the central portion of the antenna of the interrogator. To do. When the response radio wave from the transponder to the interrogation radio wave cannot be received, the interrogation radio wave is stopped. Or, if necessary, the interrogation radio wave is gradually stopped by, for example, lengthening the intermittent stop time of the interrogation radio wave when there is no response from the transponder. Further, an operation detection sensor for detecting the operation of the door opening / closing operation knob is provided, and after the detection signal of the door opening / closing operation is obtained, the inquiry radio wave is similarly transmitted and stopped.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Necessary object detection operation is carried out by using a non-contact sensor such as a visible light illuminance sensor or a pyroelectric infrared as the object detection sensor 1 provided in the central part of the antenna of an interrogator. The interrogator 2 normally stops the interrogation radio wave, and transmits the interrogation radio wave after obtaining a detection signal from an object detection sensor provided in the central part of the antenna of the interrogator. When the response radio wave from the transponder 3 to the interrogation radio wave can be received, the interrogator 2 and the transponder 3 perform necessary processing as a wireless card system. When the response radio wave from the transponder 3 cannot be received in response to the interrogation radio wave, the power consumption is reduced by stopping the transmission of the interrogation radio wave until the detection signal from the object detection sensor is obtained again. If necessary, it is possible to transmit the inquiry radio wave continuously or intermittently. Even when the response radio wave from the transponder 3 cannot be received, the interrogation radio wave is changed step by step from the continuous transmission of the interrogation radio wave to the intermittent transmission of the interrogation radio wave and the change of the strength of the radio wave output. It is also possible to stop. Alternatively, in order to mechanically detect the operation of the door opening / closing operation knob, a contact-type or non-contact-type operation detection sensor 1 is attached to the associated operation shaft part, lever part, or spring part.
Is provided to detect the operation of the door opening / closing operation knob and perform the same operation. If necessary, the object detection sensor and the operation detection sensor can be used together.

[0006]

[Embodiment 1] When the interrogator antenna and the transponder antenna which are substantially symmetrical vertically and horizontally are about the same size, one or a plurality of object detection sensors are provided at the center of the interrogator antenna.

[Embodiment 2] When the interrogator antenna whose top, bottom, left, and right are substantially symmetrical is larger than the responder antenna, one or more object detection sensors are provided at the center of the interrogator antenna.

[Embodiment 3] When the interrogator antenna which is substantially symmetrical vertically and horizontally is larger than the transponder antenna, a plurality of object detection sensors are provided in the vicinity of the central portion of the interrogator antenna at some distances from each other.

[Embodiment 4] When the interrogator antenna which is not symmetrical in the vertical and horizontal directions is larger than the transponder antenna, a plurality of object detection sensors are provided in the vicinity of the central portion of the interrogator antenna, each of which is linear with some distance. Provide in a wavy shape.

[Fifth Embodiment] An operation detection sensor 1 is provided so as to detect rotation of a shaft portion that operates when the door opening / closing operation knob is operated.

[Sixth Embodiment] An operation detection sensor 1 is provided so as to detect movement of a lever portion that operates when operating a door opening / closing operation knob.

[Embodiment 7] An operation detection sensor 1 is provided so as to detect deformation of a spring portion that operates when the door opening / closing operation knob is operated.

[0007]

EFFECTS OF THE INVENTION Since no continuous or intermittent interrogation radio waves are transmitted from the interrogator, power consumption can be reduced and the interrogator can be used for a long period of time with a small capacity power supply device such as a dry battery. As a result, the wiring required for power supply, which has been conventionally required, is not required, the installation place and the installation conditions can be expanded, and the maintenance of the device becomes easy. Further, since the normal radio wave is stopped, the security performance can be improved, and similarly, the unnecessary radio wave is not transmitted, so that the radio wave environment can be improved. In addition, the non-contact object sensor is provided at the center of the antenna, so that the responder is located at the center of the antenna of the interrogator. As a result, the positional relationship between the interrogator antenna and the transponder antenna is optimized, the communication characteristics are improved, and communication can be performed by the inquiry radio wave of lower power, and the power consumption can be reduced. Further, since there is no operation part such as a start switch exposed to the outside, weather resistance can be improved, maintenance and management of the device can be facilitated, and aesthetic constraints can be reduced.

[0008]

[Brief description of drawings]

FIG. 1 is a connection / system diagram.

FIG. 2 is an example of an operation sequence.

FIG. 3 is a plan view showing the description of the first embodiment.

FIG. 4 is a plan view showing the description of the second embodiment.

FIG. 5 is a plan view showing the description of the third embodiment.

FIG. 6 is a plan view showing the description of the fourth embodiment.

[Explanation of symbols]

1 Object detection sensor or operation detection sensor 2 interrogator 3 responder 4 Interrogator antenna 5 Transponder antenna

Claims (2)

[Claims] 1. A query radio wave is transmitted after a detection signal is obtained from a non-contact object detection sensor provided in the central part of the antenna of the interrogator, without constantly or intermittently transmitting the query radio wave from the interrogator. , An interrogator used in a wireless card system that reduces power consumption by stopping the interrogation radio wave when the response radio wave from the transponder cannot be received. 2. The inquiry radio wave is not transmitted from the interrogator continuously or intermittently, the inquiry radio wave is transmitted after the operation detection signal of the door opening / closing operation knob is obtained, and the response radio wave from the transponder cannot be received. By stopping the interrogation radio wave,
An interrogator used in a wireless card system that reduces power consumption.