AU712250B2

AU712250B2 - Vibrator drive voltage controlling device and method of the same

Info

Publication number: AU712250B2
Application number: AU65607/96A
Authority: AU
Inventors: Kuniaki Koga
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 1995-09-13
Filing date: 1996-09-12
Publication date: 1999-11-04
Anticipated expiration: 2016-09-12
Also published as: AU6560796A; EP0763389A2; KR970019164A; EP0763389A3; JPH0984075A

Description

S F Ref: 351135

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: NEC Corporation 7-1, Shiba Minato-ku Tokyo

JAPAN

Kunlaki Koga Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Vibrator Drive Voltage Controlling Device and Method of the Same The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845 VIBRATOR DRIVE VOLTAGE CONTROLLING DEVICE AND METHOD OF THE SAME BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a radio selective calling receiver that performs a calling announcement by vibrations of a vibrator, more particularly to a radio selective calling receiver in which vibratory sounds of the vibrator are restrained.

Description of the Related Art In the conventional radio selective paging receiver of this type, rotation of a motor as an essential component of the vibrator can emit noises -or abnormal sounds (generally called as abnormal sounds, hereinafter). The abnormal 15 sounds are generated by, for example, resonance in slight Vtoo*e .0 gaps between the components of the radio selective paging ""receiver and the case and rotation of the motor, which damages a fundamental function as the silent vibrator. In order to reduce the abnormal sounds generated with 20 vibrations of the vibrator, a meathod for suppressing the abnormal sounds by an electrically controlling method as well as a mechanical method is disclosed, for example, in the Japanese Patent Laid-open No. Hei 5-316016. In this S. gazette, by utilizing a characteristic that a motor S 25 revolving speed varies according to a motor drive voltage and detecting a sound pressure of the abnormal sounds, the pressure of the abnormal sounds becomes minimum.

The conventional radio selective paging receiver described above requires the sound pressure detecting circuit for detecting a sound pressure of the abnormal sounds generated by the vibrator and a variable voltage circuit for varying the motor drive voltage in multiple steps based on the detected result of the sound pressure, and has a complicated receiver construction and controlling procedure of the drive voltage. Therefore, the receiver is not easy to be made smaller and not economically efficient.

And, in the radio selective paging receiver, not only the vibrator but all the components are always requested to reduce the power consumption.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vibrator controlling device for an improved radio selective paging receiver and the method of the same.

"And, it is another object of the present invention to 20 provide a drive voltage controlling device that prevents the abnormal sounds accompanying with vibrator signals from being generated.

The vibrator drive voltage controlling device of the present invention has an output circuit for feeding a first drive voltage or a second drive voltage whose potential is lower than that of the first drive voltage, and a selecting circuit for selecting the first drive voltage at starting the vibrator and the second drive voltage after starting.

The output circuit preferably includes a first power supply for supplying the first drive voltage and a second power supply for supplying the second drive voltage.

And, the first power supply is a primary source, and the second power supply is preferably a constant voltage circuit that stabilizes the output voltage from the first power supply to give the second drive voltage.

The vibrator drive voltage controlling device of the radio selective paging receiver that paging announcement is performed by vibrations of the vibrator, according to the present invention, has an output circuit for feeding a first drive voltage to the vibrator or a second drive voltage whose potential is lower than that of the first drive voltage, and a selecting circuit for selecting the first drive voltage at paging announcement and the second drive voltage after a preset time from the paging announcement.

Further, the selecting circuit supplies a first drive signal and a second drive signal for selecting the first drive voltage and the second drive voltage, respectively, to the output circuit.

And, the output circuit has a first power supply for supplying the first drive voltage and a second power supply for supplying the second drive voltage obtained by stabilizing the first drive voltage, and feeds the first drive voltage from the first power supply by the first o drive signal and the second drive voltage from the second power supply by the second drive signal.

The selecting circuit feeds the first drive signal to the output circuit at starting paging announcement and the second drive signal to the output circuit after a preset time from the starting of the paging announcement, and the output circuit switches the first drive voltage to the second drive voltage by the switching from the first drive signal to the second drive signal.

The vibrator drive voltage controlling method of the radio selective paging receiver that paging announcement is performed by vibrations of the vibrator, according to the present invention, selects the first drive voltage at paging announcement and the second drive voltage after a preset time from the paging announcement.

And, the vibrator drive voltage controlling method of the radio selective paging receiver in which a paging announcement is performed by vibrations of the vibrator, according to the present invention, feeds a first drive signal at starting paging announcement, supplies a first drive voltage to the vibrator by receiving the first drive 0: 15. signal, generates a second drive voltage by stabilizing the first drive voltage, feeds a second drive signal after a preset time from the start of the paging announcement, and switches the first drive voltage to the second drive voltage by the switching from the first drive signal to the second drive signal.

o* Brief Description of the Drawings ."These and other objects, features and advantages of [R \LIBL]308.doc:iad this invention will become more fully apparent from the following detailed description taken with the accompanying drawings in which: Fig. 1 is a block diagram of a radio selective paging receiver showing one preferred embodiment according to the present invention, Fig. 2 is a perspective outlook to explain mounting structure of the vibrator shown in Fig. i, Fig. 3 is a chart showing a drive voltage waveform of the vibrator shown in Fig. i, Fig. 4 and 4 are operation flowcharts to explain the drive operation of the vibrator shown in Fig.

i, and Fig. 5 is a block diagram of a radio selective paging receiver showing another preferred embodiment according to the present invention.

In the drawings, the same reference numerals denote the same structural elements.

20 DESCRIPTION OF THE PREFERRED EMBODIMENTS Fig. 1 is a block diagram of a radio selective paging receiver showing one preferred embodiment according to the present invention.

In the radio selective paging receiver shown in Fig. i, a radio signal transmitted by a paging system radio base station (not illustrated) enters in a radio frequency unit 2 via an antenna i. The radio frequency unit 2 amplifies and decodes the radio signal to produce a digital signal for a decoder 3. The decoder 3 compares a paging number assigned-to the radio selective paging receiver which is written in advance in a writable read only memory (ROM) 4 with a selecting paging number contained in the digital signal from the radio frequency unit. Detecting coincidence of both the numbers, the decoder 3 starts and controls a paging announcement. The decoder 3 drives a LED driver amplifier 5 to emit LED. A receiver carrier hereat, when an announcement mode setting by operating a slide switch 17 is provided, drives a speaker driver amplifier 7 to emit sounds from a speaker 8 or drives a vibrator controller 11 to vibrate a vibrator 12.

When the radio signal contains a message signal, the decoder 3 drives a display driver 9 to make a LCD (liquid crystal display) 10 to display the message.

And, the radio selective paging receiver has a power supply 14 of the primary source for this receiver such as a dry battery, a clock circuit 15 for supplying an operation clock to the decoder 3, a reset switch 16 that halfway stops (resets) sounds for paging from the speaker 8 and vibrations of the vibrator 12 and erases the message on the LCD 10, and a RAM 18, a memory, to store data for display message. The slide switch 17, in addition to the foregoing announcement mode switching, switches ON/OFF of the power supply from the power supply 14 to the decoder 3.

Fig. 2 is a perspective outlook to explain mounting S" structure of the vibrator 12 shown in Fig. i. In Fig. 2, a mounting structure of the vibrator 12 is only shown and the other structure and electric connections are omitted.

In Fig. 2, the vibrator 12 includes a motor 22 whose revolving speed is variable according to the drive voltage supplied to the coil and a holder 21 for mounting this motor 22. The holder 21 is attached on a case 20 for the radio selective paging receiver or on a print circuit board (not illustrated) on which the receiver components are mounted. The case 20 induces vibrations due to transmission of rotation of the motor 22. The drive voltage for the vibrator 12, namely the motor drive voltage is 0.9 V to 1.7 V, the driving current is about 100 mA.

The motor revolving speed generally increases as the drive voltage increases. If the rotation of the motor resonates in a space in the case, that is, the motor revolving speed coincides with or comes close to the resonance frequency of the space, the receiver is apt to emit abnormal sounds.

0Back to Fig. i, the radio selective paging receiver has, as the power supply for driving the vibrator 13, a power supply 14 for supplying a voltage VB varying with time and a constant voltage circuit 13 for producing a stabilized voltage Vs lower than the voltage VB, by using 00 0e the power supply 14 for its power source. Which one of the 0000 two power supplies drives the vibrator 12 is selected by a vibrator controller 11 controlled by a drive signal Cl and control signal C2 from the decoder 3.

000000 0 0o The vibrator announcement operation will be described with reference to Fig. 3.

iC_ While the announcement mode of this radio selective paging receiver is set to the vibrator mode by the receiver carrier, when the decoder 3 detects a paging from the radio base station, the decoder 3 sends out the drive signal C1 to the vibrator controller 11 at time tO. And, the vibrator controller 11 closes a transistor switch S1 to connect the power supply 14 to the constant voltage circuit 13 as well as puts the switch S1 in a waiting state for connecting to the vibrator 12. Before the vibrator 12 is driven in a waiting state, a built-in transistor switch S2 of the vibrator controller 11 puts the vibrator 12 connected to the switch S1. Therefore, when the decoder 3 sends out the drive signal Cl, the vibrator 12 is immediately started by the voltage VB supplied from the power supply 14. At the same-time tO, the constant voltage circuit 13 is activated.

When the time comes to time tl after the vibrator 12 is started and a predetermined time TB passes, the decoder 3 2 sends out the control signal C2 to the vibrator controller 11. Receiving the control signal C2, the vibrator controller 11 switches the switch S2 from the power supply 14 side to the constant voltage circuit side, and the drive voltage of the vibrator 12 is switched to the voltage Vs supplied from the constant voltage circuit 13. The vibrator 12 is thereafter driven to vibrate by the drive voltage Vs.

c O When the time comes to time t2 after the predetermined time Ts passes from the drive start of the vibrator 12 by -9 the voltage Vs, the decoder 3 stops sending out the drive control signal C1 and at the same time sends out again the control signal C2. And subsequently, the vibrator controller 11 opens the switch S1 to stop driving the vibrator 12 and returns the switch S2 to the switch S1 side to reset to the waiting state.

In this radio selective paging receiver, the predetermined time TB required for starting the vibrator 12 is preferably set to less than 1 second and the predetermined time Ts needed for paging announcement is preferably set to 8 to 20 seconds in case of auto-reset.

In the embodiment described above, the power supply 14 having a high output voltage VB, capable of supplying a high current is applied at the moment of starting the vibrator 12 when a high current is needed for starting the motor. After the start of the vibrator 12, the high current to drive the motor becomes unnecessary, and the eeoo **constant voltage circuit 13 to supply the low output voltage Vs becomes the driving power supply for the vibrator 12. And the output voltage Vs is set to a voltage lower than the voltage VB such that the vibration of the avibrator 12 will emit least abnormal sounds. This voltage Vs is predetermined on the basis of experiment results on emission of abnormal sounds against drive voltage for the vibrator 12.

S" As described above, the radio selective paging receiver of this embodiment can reduce emission of abnormal sounds, because the drive voltage for the vibrator 12 is set to a low voltage that can emit least abnormal sounds for the time period Ts occupying most part of a paging announcement period. And, since the drive voltage Vs for the period Ts is set low, the receiver can reduce power consumption and extend the life of, for example, a dry battery used for the power supply 14.

Fig. 4 and 4 are operation flowcharts to explain the drive operation of the vibrator 12 according to the embodiment in Fig. i. The drive operation of the vibrator 12 will hereinafter be described with reference to Fig. 1 and 4.

The carrier of radio selective paging receiver operates the slide switch 17, turns on the power supply 14 (Y in S401), and sets the announcement mode to the vibrator mode (Y in S402). The receiver goes in the waiting mode to wait a paging (Y in S403). When a. paging signal comes in to this receiver (Y in S404), the decoder 3 decides a paging 9999 announcement by the vibrator (S405), the decoder 3 sends out the drive signal C1 to the vibrator controller 11 at .99 time tO (S406). And subsequently, the vibrator controller 11 starts the vibrator 12 by the output voltage VB from the 9 power supply 14 (S407) *e 9.

The vibrator 12 completes starting at time tl (S408), and the decoder 3 sends out the control signal to the *see 25 vibrator controller 11 (S409). And, the vibrator controller 11 drives the vibrator 12 by the output voltage "VS from the constant voltage circuit 13 (S410). For Ts seconds from this moment, vibrations by a motor spindle rotation of the vibrator 12 will give a paging announcement. If the carrier presses the reset switch 16 in Ts seconds (Y in S411), the decoder 3 stops sending out the drive signal C1 and sends out again the control signal C2 (S413). And, without pressing the reset switch 16 (N in S411), after Ts seconds pass (Y in S412), the decoder 3 stops sending out the drive signal C1 and again sends the control signal C2 (S413). The vibrator controller 11 stops driving the vibrator 12 by stopping receiving the drive signal C1 and receiving again the control signal C2. In consequence, the vibrator 12 stops vibration (S414), the paging announcement by vibration is released.

When a paging message is not available (N in S415), this radio selective paging receiver returns to the waiting state (S403). When a paging message is available on the other hand (Y in S415), the carrier confirms the message on the display unit 10 (S416), and presses the reset switch 16 (Y in S417). And then, the decoder 3 erases the display of

S..

the message (S419), and the receiver returns to a waiting 20 state (S403). Even if the carrier does not press the reset switch 16, after t seconds pass (Y in S418), auto-reset by the decoder 3 is activated and the flow goes forward to S419.

Fig. 5 is a block diagram of a radio selective paging receiver showing another preferred embodiment according to the present invention. The description of the radio selective paging receiver of this embodiment will hereafter be described mainly on the drive operation of the vibrator i ~Lil 12.

This radio selective paging receiver is provided with, as in the radio selective paging receiver in Fig. 1, an antenna i, radio frequency unit 2, ROM 4, LED driver amplifier 5, LED 6, speaker driver amplifier 7, speaker 8, display driver 9, display unit 10, vibrator 12, constant voltage circuit 13, power supply 14, clock circuit reset switch 16, slide switch 17, and RAM 18.

And, this receiver is provided with a decoder 3A which is virtually functionally identical to the decoder 3 in Fig. 1.

As to the foregoing circuits in this receiver, their operations are almost same as the ones in the radio selective paging receiver in Fig. i, their explanations 15 will be omitted to avoid wordiness except for operations characteristic to this embodiment.

The drive circuit for the vibrator 12 is provided with a switch SIA and a switch S2A in addition to the foregoing ee constant voltage circuit 13 and the power supply 14. The 20 power supply 14 supplies the output voltage VB to a first input terminal of the switch S2A. And, the constant voltage circuit receives the output voltage VB from the power supply 14 directly to produce the output voltage Vs and supplies the output voltage VS to a second input terminal of the switch S2A. An output terminal of the switch S2A is connected to a power supply terminal of the vibrator 12. A ground terminal of the vibrator is connected to an input terminal of the switch connected to an input terminal of the switch SlA, and-a ground terminal of the switch SlA is connected to the ground potential.

The switch S2A usually (control signal C2A is in LOW level) feeds a voltage approx. VB, expressed as VB hereinafter from the power supply 14 to the vibrator 12, and switches the voltage feeding to the vibrator 12 to a voltage approx. Vs, expressed as Vs hereinafter) from the constant voltage circuit 13. The switch S2A uses an emitter of a PNP type transistor Q1 for the first input terminal and a collector of a NPN type transistor Q2 for the second input terminal, and uses both a collector of the transistor Q1 and an emitter of the transistor Q2 for an output terminal. In the switch S2A, the transistor Q1 15 turns ON in a normal state (control signal is in LOW level) when the control signal C2A is not fed to bases of the transistor Ql and Q2 commonly connected as used for a control terminal, and the transistor Q2 switches to turn ON 0* when the control signal C2A is fed to the control terminal.

20 The switch SlA turns ON to connect the ground terminal of the vibrator 12 to the ground potential when the drive signal ClA in HIGH level is fed to a control terminal from the decoder 3A. In this switch SlA, a collector of a NPN type transistor Q3 is used for an input terminal, an emitter for a ground terminal, and the drive signal ClA is applied to a base of the transistor Q3, the control terminal, via a resistor Rl.

Next, the drive operation'of the vibrator 12 in the radio selective paging receiver according to the second embodiment will be described with reference to Fig. 5 and 3.

When the announcement mode of this radio selective paging receiver is in the vibrator mode and the decoder 3A detects a paging signal from the radio base station, the decoder 3A sends out a HIGH level drive signal ClA to the switch SlA at time tO. And, the switch SlA goes ON and the voltage VB from the power supply 14 is supplied to the vibrator 12, and the vibrator 12 is started to vibrate.

Since the control signal C2A is in LOW level at this moment, the transistor Q1 is ON. After the starting of the vibrator 12, when the time passes the predetermined time period TB and comes to time tl, the decoder 15 3A sends out a HIGH level control signal C2A to the switch S2A. Receiving the control signal C2A, the switch S2A feeds the voltage Vs from the constant voltage circuit 13 to the output terminal, the drive voltage for the vibrator 12 is switched to the voltage Vs from the constant voltage 20 circuit 13. The vibrator 12 is driven to vibrate by the voltage Vs thereafter.

After the drive voltage is switched, when the time passes the predetermined time Ts for paging announcement and comes to time t2, the decoder 3A stops sending out the drive signal C1A and the control signal C2A. Then the switch SlA goes off, and the vibrator 12 is stopped to vibrate. At the same time, the switch S2A returns the power supply source to the first input terminal.

~~i As described above, since the radio selective paging receiver according to the second embodiment operates in the same manner as the radio selective paging receiver according to the first embodiment, emission of abnormal sounds can be restrained and the life of dry batteries used for the power supply 14 can be extended.

As described hereinabove, since on starting a paging announcement the 12 is driven to vibrate by the first power supply giving the first output voltage and after starting the paging announcement the 12 is driven to vibrate by the second power supply giving the second output voltage lower than the first output voltage, the present invention has an effect that emission of abnormal sounds can be restrained while the vibrator vibrates.

15 And, since after starting-the vibrator the drive voltage goes down to a voltage lower than the output voltage of the first power supply, the present invention has an effect that the life of the first power supply can be extended.

20 While the invention has been described with reference to specific embodiments thereof, it will be appreciated by those skilled in the art that numerous variations, modifications, and embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being with in spirit and scope of the invention.

Claims

2. A vibrator drive voltage controlling device as claimed in claim 1, wherein said output means consists of a first power supply for supplying said first drive voltage and a second power supply for supplying said second drive gee• voltage.
3. A vibrator drive voltage controlling device as claimed in claim 2, wherein said first power supply is a primary source and said second power supply is a constant voltage circuit that stabilizes an output voltage from said a. first power supply to give said second drive voltage. 20 4. A vibrator drive voltage controlling device for a radio selective paging receiver that a paging announcement is performed by vibrations of said vibrator, said vibrator drive voltage controlling device comprising: an output means for feeding a first drive voltage to said vibrator or a second drive voltage whose potential is lower than that of said first drive voltage; and a selecting means for selecting said first drive voltage at said paging announcement and selecting said second drive voltage after a predetermined time from said paging announcement. A vibrator drive voltage controlling device as claimed in claim 4, wherein said selecting means supplies a first drive signal and a second drive signal for selecting said first drive voltage and said second drive voltage, respectively, to said output means.
6. A vibrator drive voltage controlling device as claimed in claim 5, wherein said output means has a first power supply for supplying said first drive voltage and a second power supply for supplying said second drive voltage obtained by stabilizing said first drive voltage, and 9 supplies said first drive voltage from said first power 9*9* supply by said first drive signal and supplies said second drive voltage from said second power supply by said second drive signal. 20 7. A vibrator drive voltage controlling device as claimed in claim 6, wherein said selecting means feeds said first drive signal to said output means at starting said paging announcement and feeds said second drive signal to said output means after a predetermined time from said starting of said paging announcement, and said output means -18- switches said first drive voltage to said second drive voltage by a switching from said first drive signal to said second drive signal.
8. A vibrator drive voltage controlling device as claimed in claim 6, wherein said selecting means further comprises: a first switch in which an input terminal is connected to a ground terminal of said vibrator, an output terminal is connected to a ground potential, and said input terminal is connected to said output terminal by receiving at a control terminal said second drive signal sent out by said selecting means; and a second switch in which a first input terminal is connected to said output terminal of said first power supply, a second input terminal is connected to said output terminal of said second power supply, an output terminal is connected to said power supply terminal of said vibrator, and when a control terminal receives said second control signal from said selecting means after a predetermined time passes from said sending-out 15 of said second drive signal said connection to said output terminal is switched from said first input terminal to said second input terminal.
9. A vibrator drive voltage controlling method for a radio selective paging receiver in which a paging announcement is performed by vibrations of said vibrator, wherein: 2c 2o a first drive voltage is selected at said paging announcement; [R\LIBL]308.doc:iad and a second drive voltage is selected after a predetermined time from said paging announcement. A vibrator drive voltage controlling method for said radio selective paging receiver that a paging announcement is performed by vibrations of said vibrator, wherein: a first drive signal is fed at starting a paging announcement; a first drive voltage is supplied to said vibrator by receiving said first drive signal; a second drive voltage is generated by stabilizing said first drive voltage; a second drive signal is fed after a predetermined time *r from said start of said paging announcement; and S 0 15 said first drive voltage is switched to said second O. drive voltage by said switching from said first drive signal to said second drive signal. 0~.w
11. Apparatus substantially as described herein with reference to the accompanying drawings. C.
12. Method substantially as described herein with reference to the accompanying drawings. DATED this NINTH day of SEPTEMBER 1996 NEC Corporation Patent Attorneys for the Applicant SPRUSON FERGUSON