Portable radio apparatus having battery saved channel scanning function
First Claim
1. A portable radio apparatus comprising a receiving section capable of being tuned to any of a plurality of channels, a switch circuit for controlling a supply of battery power to said receiving section, and a control section connected to said receiving section and said switch circuit, said control section including:
- channel scanning means for performing a channel scanning in which said receiving section is sequentially tuned through said plurality of channels;
first detecting means coupled to said channel scanning means for detecting an electric field strength on each of said plurality of channels;
second detecting means coupled to said channel scanning means and to said first detecting means for detecting predetermined data in a channel among said plurality of channels, said channel having the strongest electric field strength;
means responsive to a lack of predetermined data appearing on said channel detected by said second detecting means for changing over said channel scanning means to an intermittent scanning operation after a first predetermined time period, said intermittent scanning operation repeating cycle combined by one round scanning of said plurality of channels and interruption of a second predetermined time period, andmeans coupled to said switch circuit for switching off said battery power to said receiving section during said second predetermined time period, where said channel scanning is cyclically and continuously performed during said first predetermined time period.
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Abstract
A portable radio apparatus may operate in a battery saving mode on any one of a plurality of channels, in order to communicate with a central office. The apparatus selects a channel for its use on a basis of the strength of the electrical fields on the various channels. During an initial period the apparatus scans continuously for a channel. If no channel is found during the initial period, the apparatus switches to an intermittent scan, with power down between the intermittent scan, thus providing the battery saving mode.
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Citations
16 Claims
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1. A portable radio apparatus comprising a receiving section capable of being tuned to any of a plurality of channels, a switch circuit for controlling a supply of battery power to said receiving section, and a control section connected to said receiving section and said switch circuit, said control section including:
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channel scanning means for performing a channel scanning in which said receiving section is sequentially tuned through said plurality of channels; first detecting means coupled to said channel scanning means for detecting an electric field strength on each of said plurality of channels; second detecting means coupled to said channel scanning means and to said first detecting means for detecting predetermined data in a channel among said plurality of channels, said channel having the strongest electric field strength; means responsive to a lack of predetermined data appearing on said channel detected by said second detecting means for changing over said channel scanning means to an intermittent scanning operation after a first predetermined time period, said intermittent scanning operation repeating cycle combined by one round scanning of said plurality of channels and interruption of a second predetermined time period, and means coupled to said switch circuit for switching off said battery power to said receiving section during said second predetermined time period, where said channel scanning is cyclically and continuously performed during said first predetermined time period. - View Dependent Claims (2, 3, 4, 5, 7, 8, 13)
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6. A portable radio apparatus as claimed in 1, wherein said first detecting means comprises an envelope detector for detecting an envelope of a signal which is outputted by an intermediate frequency (IF) stage of said receiving section, and an analog-to-digital (A/D) converter for converting the output of said envelope detector to a digital signal.
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9. A portable radio apparatus having an intermittent scanning function, comprising:
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a radio seciton capable of being tuned to any of a pluraltiy of channels; a power switch for establishing and interrupting a supply of power to said radio section; control means effective while said apparatus is in a waiting condition for controlling said radio section to sequentially scan control channels to measure reception levels corresponding to electric field strength on said respective control channels, said control means tuning said radio section to one of said control channels which has the highest reception level and, if that one channel does not respond, to another of said control channels which has the second highest reception level, said control means repeating said channel scanning when no data is received, and means for controlling said power switch to interrupt a supply of power to corresponding portions of said apparatus, except for at least a timer section when data is not received for a predetermined period of time; means for resuming said channel scanning by feeding power to said portions, which have been disconnected from said radio section, at predetermined time intervals after the interruption of the power supply; and means for interrupting said intermittent scanning and executing said channel scanning when a predetermined condition is reached. - View Dependent Claims (10)
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11. A method of scanning channels of a portable radio apparatus, comprising the steps of:
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tuning a receiving section to a plurality of channels to detect the electric field strength of the respective channels; selecting at least one channel among said plurality of channels having the strongest electric field strength; deciding whether or not data is present on said at least one channel; when data is not present on said at least one channel, cyclically and continuously tuning said receiving section to the respective channels; when said cyclic and continuous tuning operation has continued for more than a predetermined period of time while data is not present on any of said channels, intermittently tuning said receiving section to said respective channels; and feeding power to said receiving section continuously during said continuous tuning operation and intermittently during said intermittent tuning operation. - View Dependent Claims (12)
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14. A portable radio apparatus which may seize and operate on one of a plurality of channels, said apparatus comprising:
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a switchable power supply means for selectively supplying or not supplying power to said apparatus; first detector means for detecting the strength of electric fields on said channels; channel scanning means for scanning said channels to sequentially tune said apparatus to one of said channels on a basis of the strength of electric fields detected by said first detector means; second detector means for detecting data on one of said channels to which said apparatus is tuned; control means for controlling said switchable power supply to continuously supply said power to said apparatus during an initial scanning period; and battery saving means responsive to lack of data detection by said second detector means during said initial scanning period for controlling said switchable power supply to intermittently supply said power to said apparatus during intermittent scanning periods. - View Dependent Claims (15)
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16. A portable radio apparatus having a receiving section and a switch for controlling a supply of battery power to said receiving section, said radio apparatus comprising:
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means for sequentially tuning a plurality of channels to detect the strength of any electric field on the respective channels; means for storing the strength of the electric field of the respective channels detected by said tuning means; means responsive to the strength of the electric field as stored in said storing means for selecting at least one channel having the strongest strength of electric field; means coupled to said selecting means for judging whether or not predetermined data are contained in the selected channel; means responsive to no predetermined data appearing on said selected channel for changing over said tuning means to an intermittent operation after a first predetermined time period, said intermittent operation repeating a cycle combined by one round of tuning operations of said plurality of channels and interruption of a second predetermined time period, and means coupled to said switch for switching off said battery power to said receiving section during said second predetermined time period, wherein the tuning operation of said tuning means is cyclically and continuously performed within said first predetermined time period.
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Specification