Information access system and active-type contactless information storage device
First Claim
1. An information access system for accessing information stored in a contactless information storage device, comprising:
- a reader/writer device connected to an information processing apparatus, and being adapted to continually transmit an ID request signal at a first frequency in transmission time periods in a transmission cycle and to be continuously ready to receive an RF signal at a second frequency which is different from the first frequency; and
an active-type contactless information storage device having;
a memory,a control unit,a battery,a timer for measuring time,a receiver unit for sensing, using power supplied from the battery,a carrier of an RF signal at the first frequency for detection, anda transmitter unit for transmitting, using power supplied from the battery, a response signal at the second frequency when the ID request signal is received, whereinthe control unit controls, in carrier sensing periods occurring in a carrier sensing cycle, the transmitter unit to be in an inactive state and the receiver unit to be in an active state and sense, using power supplied from the battery, a carrier of an RF signal at the first frequency, the carrier sensing period being shorter than the transmission time period of the ID request signal, the carrier sensing cycle being longer than the transmission cycle of the ID request signal, the carrier sensing cycle being determined according to the timer,when the receiver unit senses and detects a carrier of an RF signal at the first frequency in one of the carrier sensing periods, the control unit causes the receiver unit to receive, using power supplied from the battery, the ID request signal before a subsequent one of the carrier sensing periods, and, in response to the ID request signal, causes the transmitter unit to transmit, using power supplied from the battery, a response signal at the second frequency carrying an ID of the active-type contactless information storage device stored in the memory before the subsequent carrier sensing period; and
when the receiver unit detects no carrier in one of the carrier sensing periods, the control unit controls the receiver unit and the transmitter unit to be in the inactive state during a non-carrier-sensing period between the one carrier sensing period and a subsequent one of the carrier sensing periods.
1 Assignment
0 Petitions
Accused Products
Abstract
An information access system comprises a reader/writer for continually transmitting an ID request signal at a first frequency and being continuously ready to receive an RF signal at a second frequency, and an active contactless information storage device having a receiver for sensing a carrier of an RF signal at the first frequency, and a transmitter for transmitting a response signal at the second frequency when the ID request signal is received. When the receiver senses a carrier of an RF signal at the first frequency in a particular predetermined period, the receiver receives further the ID request signal, and, in response to the ID request signal, the transmitter transmits a response signal at the second frequency carrying an ID of the storage device stored. In the carrier sensing, the controller causes the receiver to be in an active state and the transmitter to be in an inactive state in the predetermined periods. When the receiver attempts to sense a carrier of the RF signal at the first frequency in a particular predetermined period but detects no carrier, the controller controls the receiver and the transmitter to maintain the inactive state during a sleep period between the particular predetermined period and the subsequent predetermined period.
28 Citations
15 Claims
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1. An information access system for accessing information stored in a contactless information storage device, comprising:
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a reader/writer device connected to an information processing apparatus, and being adapted to continually transmit an ID request signal at a first frequency in transmission time periods in a transmission cycle and to be continuously ready to receive an RF signal at a second frequency which is different from the first frequency; and an active-type contactless information storage device having; a memory, a control unit, a battery, a timer for measuring time, a receiver unit for sensing, using power supplied from the battery, a carrier of an RF signal at the first frequency for detection, and a transmitter unit for transmitting, using power supplied from the battery, a response signal at the second frequency when the ID request signal is received, wherein the control unit controls, in carrier sensing periods occurring in a carrier sensing cycle, the transmitter unit to be in an inactive state and the receiver unit to be in an active state and sense, using power supplied from the battery, a carrier of an RF signal at the first frequency, the carrier sensing period being shorter than the transmission time period of the ID request signal, the carrier sensing cycle being longer than the transmission cycle of the ID request signal, the carrier sensing cycle being determined according to the timer, when the receiver unit senses and detects a carrier of an RF signal at the first frequency in one of the carrier sensing periods, the control unit causes the receiver unit to receive, using power supplied from the battery, the ID request signal before a subsequent one of the carrier sensing periods, and, in response to the ID request signal, causes the transmitter unit to transmit, using power supplied from the battery, a response signal at the second frequency carrying an ID of the active-type contactless information storage device stored in the memory before the subsequent carrier sensing period; and when the receiver unit detects no carrier in one of the carrier sensing periods, the control unit controls the receiver unit and the transmitter unit to be in the inactive state during a non-carrier-sensing period between the one carrier sensing period and a subsequent one of the carrier sensing periods. - View Dependent Claims (2, 3, 4, 5)
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6. An active-type contactless information storage device comprising:
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a memory; a battery; a timer for measuring time; a receiver unit being adapted to sense, using power supplied from the battery, a carrier of an ID request signal at a first frequency from a reader/writer device for detection, when the active-type contactless information storage device approaches the reader/writer device; a transmitter unit for modulating a carrier with data and then transmitting a response signal at a second frequency to the reader/writer device, while using power supplied from the battery; and a control unit for controlling the receiver unit and the transmitter unit, wherein the control unit controls, in carrier sensing periods occurring in a carrier sensing cycle, the transmitter unit to be in an inactive state and the receiver unit to be in an active state and sense, using power supplied from the battery, a carrier of an RF signal at the first frequency, the carrier sensing period being shorter than a time period of the ID request signal., the carrier sensing cycle being longer than a cycle of occurring the ID request signal, the carrier sensing cycle being determined according to the timer, when the receiver unit senses and detects a carrier of an RF signal at the first frequency in one of the carrier sensing periods, the control unit causes the receiver unit to receive, using power supplied from the battery, the ID request signal before a subsequent one of the carrier sensing periods, and, in response to the ID request signal, causes the transmitter unit to transmit, using power supplied from the battery, a response signal at the second frequency carrying an ID of the active-type contactless information storage device stored in the memory before the subsequent carrier sensing period; and when the receiver unit detects no carrier in one of the carrier sensing periods, the control unit controls the receiver unit and the transmitter unit to be in the inactive state during a non-carrier-sensing period between the one carrier sensing period and a subsequent one of the carrier sensing periods.
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7. An active-type contactless information storage device comprising:
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a memory; a battery; a timer for measuring time; a receiver unit being adapted to sense, using power supplied, from the battery, a carrier of an ID request signal at a first frequency from a reader/writer device for detection and reproduce an encoded ID request, when the active-type contactless information storage device approaches the reader/writer device; a data decoding unit for decoding the encoded ID request to thereby reproduce a decoded ID request; an encoding unit for retrieving an ID from the memory, and then encoding the ID to thereby generate the encoded data; a transmitter unit for modulating a carrier with the generated encoded data and then transmitting a response signal at a second frequency to the reader/writer device, while using power supplied from the battery; and a control unit for controlling the receiver unit, the data decoding unit, the encoding unit and the transmitter unit, wherein the control unit controls, in carrier sensing periods occurring in a carrier sensing cycle, the transmitter unit to be in an inactive state and the receiver unit to be in an active state and sense, using power supplied from the battery, a carrier of an RF signal at the first frequency, the carrier sensing period being shorter than a time period of the ID request signal, the carrier sensing cycle being longer than a cycle of occurring the ID request signal, the carrier sensing cycle being determined according to the timer, when the receiver unit senses and detects a carrier of an RF signal at the first frequency in one of the carrier sensing periods, the control unit causes the receiver unit to receive, using power supplied from the battery, the ID request signal before a subsequent one of the carrier sensing periods, then causes the data decoding unit to reproduce the ID request, then in response to the ID request, causes the encoding unit to encode the ID retrieved from the memory, and then causes the transmitter unit to transmit, using power supplied from the battery, the response signal at the second frequency carrying the encoded ID before the subsequent carrier sensing period, and when the receiver unit detects no carrier in one of the carrier sensing periods, the control unit controls the receiver unit and the transmitter unit to be in the inactive state during a non-carrier-sensing period between the one carrier sensing period and a subsequent one of the carrier sensing periods. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. An information access system for accessing information stored in a contactless information storage device, comprising:
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a reader/writer device connected to an information processing apparatus, and being adapted to continually transmit an ID request signal at a first frequency in transmission time periods in a transmission cycle and to be continuously ready to receive an RF signal at a second frequency which is different from the first frequency; and an active-type contactless information storage device having; a memory, a control unit, a timer for measuring time, a receiver unit for sensing, a carrier of an RF signal at the first frequency for detection, and a transmitter unit for transmitting, a response signal at the second frequency when the ID request signal is received, wherein the control unit controls, in carrier sensing periods occurring in a carrier sensing cycle, the transmitter unit to be in an inactive state and the receiver unit to be in an active state and sense a carrier of an RF signal at the first frequency, the carrier sensing period being shorter than the transmission time period of the ID request signal, the carrier sensing cycle being longer than the transmission cycle of the ID request signal, the carrier sensing cycle being determined according to the timer, when the receiver unit detects a carrier of an RF signal at the first frequency in one of the carrier sensing periods, the control unit causes the receiver unit to further receive the ID request signal before a subsequent one of the carrier sensing periods, and, in response to the ID request signal, further causes the transmitter unit to transmit a response signal at the second frequency that carries an ID of the active-type contactless information storage device stored in the memory before the subsequent carrier sensing period, and when the receiver unit detects no carrier in one of the carrier sensing periods, the control unit controls the receiver unit and the transmitter unit to be in the inactive state during a non-carrier-sensing period between the one carrier sensing period and a subsequent one of the carrier sensing periods.
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15. An active-type contactless information storage device comprising:
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a memory; a timer for measuring time; a receiver unit being adapted to sense a carrier of an ID request signal at a first frequency from a reader/writer device for detection, when the active-type contactless information storage device approaches the reader/writer device; a transmitter unit for modulating a carrier with data and then transmitting a response signal at a second frequency to the reader/writer device; and a control unit for controlling the receiver unit and the transmitter unit, wherein the control unit controls, in carrier sensing periods occurring in a carrier sensing cycle, the transmitter unit to be in an inactive state and the receiver unit to be in an active state and sense a carrier of an RF signal at the first frequency, the carrier sensing period being shorter than a time period of the ID request signal, the carrier sensing cycle being longer than a cycle of occurring the ID request signal, the carrier sensing cycle being determined according to the timer, when the receiver unit detects a carrier of an RF signal at the first frequency in one of the carrier sensing periods, the control unit causes the receiver unit to further receive the ID request signal before a subsequent one of the carrier sensing periods, and, in response to the ID request signal, further causes the transmitter unit to transmit a response signal at the second frequency carrying an ID of the active-type contactless information storage device stored in the memory before the subsequent carrier sensing period; and when the receiver unit detects no carrier in one of the carrier sensing periods, the control unit controls the receiver unit and the transmitter unit to be in the inactive state during a non-carrier-sensing period between the one carrier sensing period and a subsequent one of the carrier sensing periods.
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Specification