JPH03226029A - Selective radio call receiver - Google Patents

Abstract

PURPOSE:To prevent the deterioration in the sensitivity caused by affecting a power supply of a radio section with the noise generated from an informing means by driving the notice means with a secondary battery being a separate power supply for the radio section. CONSTITUTION:A radio signal received by an antenna 101 is amplified and demodulated by a radio section 102 and sent to a decoder section 103 as a reception data. The decoder section 103 compares an individual selective call number registered in a ROM 105 with a received selective call number and informs it to a selective radio call receiver carrier in a ring tone or by means of vibration or the like when both are coincident with each other. The ring tone is sounded from a speaker 107 and the vibration is delivered by using a vibrator 109 in which a motor is driven while its shaft is fitted with an eccentric weight. A battery 111 is used for the power supply. Thus, noise generated from the speaker 107 or the vibrator 109 does not affect onto the power line of the radio section 102.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radio selective call receiver, and more particularly to a radio selective call receiver using an orthogonal detection method.

[Prior Art] Conventional radio selective calling receivers have often adopted an orthogonal detection method in order to meet the demand for miniaturization. FIG. 3 shows a circuit of a radio section using this orthogonal detection method. Third
In the figure, 301 is a mixer circuit, 302 is a channel filter, 303 is a limiter circuit, 304 is a demodulation circuit,
305 is a waveform shaping circuit, 306 is a 90 degree phase shifter, 307
is a local oscillator circuit.

When the orthogonal detection method is used, the intermediate frequency becomes zero because the local oscillation frequency and the line frequency are equal.

Therefore, there is no image frequency, and filters are not required in the high frequency amplifier and intermediate frequency amplifier, making it suitable for miniaturization. Furthermore, since the channel filter 302 shown in FIG. 3 has an intermediate frequency of zero, it can be configured with a low-frequency active filter, can be realized on an integrated circuit, and is suitable for miniaturization.

A conventional radio selective calling receiver using this radio section is shown in FIG.

In FIG. 2, a radio signal received by an antenna 201 is amplified and demodulated by a radio section 202, and sent to a decoder section 203 as received data. The decoder unit 203
The individual selective calling number registered in the M205 is compared with the received selective calling number, and if the two match, the person carrying the wireless selective calling receiver is notified by sound, vibration, etc. Sound is reported by a speaker 207, and vibration is reported by a vibrator 209, which rotates an eccentric weight attached to the shaft of a motor.

On the other hand, the low voltage detection circuit 210 notifies the decoder unit 203 that the power supply voltage has fallen below the minimum required voltage to operate the wireless unit 202 stably, and causes the speaker 207 to sound via the speaker drive unit 206. A sound is emitted to prompt the person carrying the radio selective calling receiver to replace the battery 211, thereby preventing the radio section 202 from operating unstablely and deteriorating its sensitivity.

[Problem to be Solved by the Invention] The radio selective call receiver using the orthogonal detection method in the radio section described above has the problem that when receiving an individual selective call signal, the speaker 2
07 or the vibrator 209 is activated to notify the person carrying the wireless selective call receiver that there has been a call.

The radio section 202 becomes unstable when the power supply voltage decreases, causing deterioration in sensitivity. In particular, in a radio selective calling receiver using an orthogonal detection method, when the speaker 207 or the vibrator 209 is driven, There is a problem in that the generated noise affects the channel filter 302 and limiter circuit 303 of the radio section 202, suppresses the signal, and causes sensitivity deterioration.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems, and aims to prevent deterioration in sensitivity due to noise generated from the notification means being applied to the power supply of the radio section. To achieve this objective, the line frequency and local oscillator frequency are made equal,
In a radio selective calling receiver using a quadrature detection method in which beats of the received frequency and local oscillation frequency are extracted by a mixer and demodulated via a channel filter, there is a notification means for notifying a call, and a power source for driving the notification means. It is configured to include a secondary battery and a charging circuit for charging the secondary battery.

Preferably, the charging circuit is also configured to boost the voltage.

More preferably, the charging circuit is composed of a booster circuit and a backflow blocking diode. [Function] In the wireless selective calling receiver having the above configuration, a secondary battery separate from the power source of the wireless section is provided, and the secondary battery By driving the notification means, it is possible to prevent deterioration in sensitivity due to noise generated from the notification means being applied to the power supply of the wireless section.

[Example code] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing an embodiment of a wireless selective calling receiver according to the present invention.

In FIG. 1, a radio signal received by an antenna 101 is amplified and demodulated by a radio section 102, and sent to a decoder section 103 as received data. The decoder section 103
The individual selective calling number registered in the M105 is compared with the received selective calling number, and if the two match, the person carrying the wireless selective calling receiver is notified by ringing, vibration, etc. Sound is reported by a speaker 107, and vibration is reported by a vibrator 109, which rotates an eccentric weight attached to the shaft of a motor.

The speaker 107 is driven by a speaker drive section 108 under the control of the decoder section 103, and the vibrator 1
09 is driven by the vibrator drive section 108 and the decoder section 1.
This is done under the control of 03. The crystal oscillator 104 is a clock generating oscillator that operates the decoder section 103.

A battery 111 is used as a power source, and a low voltage detection circuit 110
notifies the decoder unit 103 that the battery voltage has fallen below the minimum required voltage for receiving operation, causes the speaker 107 to sound via the speaker drive unit 106, and alerts the user of the wireless selective calling receiver to the battery 111. encourage the exchange of The current flowing through the speaker 107 and the vibrator 109 is a secondary battery 114 in which the voltage of the battery 111 is boosted by a DC-DC converter 112 and charged via a diode 113.
Supplied from.

Therefore, noise generated from the speaker 107 or the vibrator 109 does not affect the power line of the wireless section 102. Here, the diode 113 is a secondary battery 114
It is used to prevent the reverse flow of current from the

[Effects of the Invention] As explained above, the present invention uses a quadrature detection method in which the line frequency and the local oscillation frequency are made equal, the received frequency and the beat of the local oscillation frequency are extracted by a mixer, and demodulated via a channel filter. The wireless selective calling receiver using the wireless selective calling receiver is configured to include a notification means for notifying a call, a secondary battery as a driving power source for the notification means, and a charging circuit for charging the secondary battery.

In this way, by driving the notification means with a secondary battery that is separate from the power supply of the radio section, it is possible to prevent deterioration in sensitivity due to noise generated from the notification means riding on the power supply of the radio section. becomes.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a radio selective call receiver according to the present invention, FIG. 2 is a block diagram showing a conventional radio selective call receiver, and FIG. 3 is a block diagram showing a conventional radio selective call receiver. FIG. 01 02 03 04 05 06 07 08 09 10 Antenna radio section Decoder section Crystal oscillator OM Speaker drive section Speaker vibrator drive section Vibrator Low voltage detection circuit 1 2 3 4 Battery DC-DC converter diode Secondary battery

Claims (2)

[Claims] (1) In a radio selective paging receiver that uses an orthogonal detection method in which the line frequency and local oscillation frequency are made equal, a mixer extracts the beats of the received frequency and local oscillation frequency, and demodulation is performed via a channel filter. A wireless selective calling receiver comprising: a notification means for notifying the user; a secondary battery as a driving power source for the notification means; and a charging circuit for charging the secondary battery. (2) The radio selective calling receiver according to claim 1, wherein the charging circuit also boosts the voltage. (3) The radio selective calling receiver according to claim 1, wherein the charging circuit is comprised of a booster circuit and a reverse current blocking diode.