Abstract:
An apparatus for informing a holder or user of the apparatus of a predetermined state by providing a vibratory sensation to the holder or user. The vibrations produced by the apparatus produces in a manner so as to prevent substantial movements of the apparatus even when left unattended. The apparatus includes a motor attached to a housing and a controller for actuating the motor to rotate a shaft. The controller actuates the motor to rotate the shaft in forward and reverse directions alternately at predetermined intervals in response to reception of an incoming signal.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an apparatus for portable equipment such as a cellular phone, a beeper, or a portable electronic device having a timer function, in particular, an apparatus for informing a user of predetermined incoming information such as a call or a set time by vibrations. 
     2. Description of the Related Art 
     A cellular phone with a vibrator function is well known. The phone serves to inform its holder of an incoming call not only by tone but also by vibrations of the phone housing. 
     The cellular phone includes a motor (vibrator) attached in a housing and having an eccentric weight. The eccentric weight has a center of gravity deviated from a rotary shaft of the motor by a predetermined distance. Thus, the vibrator function is achieved as follows. First, the rotation of the motor in one direction in response to an incoming call rotates the eccentric weight in the circumferential direction of a predetermined radius about the rotary shaft. Therefore, the housing to which a stator of the motor is attached receives the reaction force generated by the movement of the eccentric weight to forceably vibrate itself. Then, the vibration can directly propagate to a user to inform him/her of the incoming call. The vibrator function is suitable when the user wants to perceive an incoming call without troubling adjacent people with the sound tone. 
     To enable the user of the cellular phone to sense the vibration of the housing of the cellular phone to perceive the incoming call, he/she has to always hold the cellular phone in such a manner that a part of his/her body is in contact with the housing. When the user leaves the cellular phone on a table or away from his/her body, and when the cellular phone vibrates the housing in response to an incoming call, the cellular phone may experience substantial movement due to the vibration from the original position on the table. As a result, the phone may sometimes drop from the table. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     In order to overcome the above problems, a main object of the invention is to provide an apparatus for informing a user of the reception of predetermined information by means of the vibration, which can stay within only a predetermined area from the original position upon receiving an incoming call. 
     According to one aspect of the invention, the present invention features an apparatus for vibrating itself to inform a user of the reception of predetermined information. The apparatus comprises a housing, a motor attached to a housing, a shaft rotatably driven by the motor, and means for rotating the shaft to vibrate the housing, wherein the means for rotating rotates said shaft in forward and reverse directions alternately at predetermined intervals in response to the reception. Therefore, when the apparatus receives predetermined incoming information such as a call, the shaft then rotates in forward and reverse directions alternately at predetermined intervals to vibrate the housing, thereby informing a user of the reception of the predetermined information. 
     Even when the apparatus is left on a table without being directly held by the user, the housing is subjected to forces generated by rotating the shaft in forward and reverse directions alternately at predetermined intervals. Thus, the apparatus can stay on the table while vibrating around an original position on which the apparatus is positioned. As a result, the apparatus is protected from substantial movement from the original position. 
    
    
     BRIEF EXPLANATION OF THE DRAWINGS 
     The aforementioned aspects and other features of the invention are explained in the following description, taken in connection with the accompanying drawing figures wherein: 
     FIG. 1 is a block diagram showing a cellular phone with one embodiment of an apparatus according to the invention; 
     FIG. 2A is a perspective view of a motor; 
     FIG. 2B is a front view of the motor; 
     FIGS. 3A-3B are diagrams showing waveforms of signals to drive the motor by the driving unit in response to an incoming call; 
     FIGS. 4A-4D are schematic views showing the rotation of the motor in which the center of gravity G of an eccentric weight is moving; and 
     FIGS. 5A-5B are schematic diagrams showing a force applied to a cellular phone when the shaft of the motor is rotating in one direction. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Preferred embodiments of the invention will now be described hereinbelow with reference to the drawings. 
     FIG. 1 is a block diagram showing a cellular phone  1  including one embodiment of an apparatus according to the invention. 
     Referring to FIG. 1, the cellular phone  1  includes an antenna  7 , and a high frequency signal processor  10  in a housing  1   a . The high frequency signal processor  10  comprises a DPX (duplexer)  11 , matching circuit  12 , a high frequency amplifier  13 , a demodulator  14 , a modulator  15 , a high frequency amplifier  16 , and a matching circuit  17 . 
     The antenna  7  receives signals, and transmits the signals to the DPX  11  operating as a branching filter. The DPX  11  extracts only the received signals and supplies the extracted signals to the high frequency amplifier  13  via the matching circuit  12 . The high frequency amplifier  13  amplifies an input signal by a predetermined gain to supply the amplified signal to the demodulator  14 . The demodulator  14  then converts the amplified signal to a lower frequency signal as an audio frequency signal. The low frequency signal processor  20  amplifies the demodulated signal. The resultant signal is emitted as the received tone from a speaker  21 . 
     The high frequency signal processor  10  includes a level detector  19  to detect intensity (level) of the received signal. A CPU  23  controls a display controller  25  to display the intensity (level) of the received signal onto a display unit  26 . 
     A voice signal (transmission tone) supplied through a microphone  22  is amplified by a low frequency signal processor  20 , and then modulated to a transmission signal by the modulator  15 . The high frequency signal modulated to a transmission signal is amplified by the high frequency amplifier  16 . The amplified signal is then supplied from the DPX  11  to the antenna  7  via the matching circuit  17 , and radiated as a transmission signal. 
     The CPU  23  not only controls an operation regarding the operations upon transmission and reception of the cellular phone  1 , but also produces a reception tone from a speaker (not shown) in response to an incoming call to inform a user that the phone is receiving the call. The CPU  23  further controls the display controller  25  by means of ten-key buttons provided on an operating unit  24  upon transmission, thereby allowing the telephone number of a partner to be displayed on the display unit  26 . It is noted that a program regarding the operation for the CPU has previously been stored in a ROM  27 . 
     The CPU  23  has another function for informing the user that the cellular phone  1  is receiving a call by means of vibration of the housing  1   a  in place of the reception tone in response to a command from the operating unit  24 . 
     Therefore, when a command to turn on a vibrator is sent from the operating unit  24  to the CPU  23 , the CPU  23  controls the low frequency signal processor  20  in response to an incoming call to stop the transmission of the reception tone to the speaker. The CPU  23  then controls a driving unit  28  which activates a motor  29  fixed to the housing  1   a  so as to repeat a set of forward and reverse motor rotations, so as to vibrate the housing and inform the user of the incoming call. 
     FIG. 2A is a perspective view of a motor  29 . FIG. 2B is a front view showing the motor  29  installed in the housing  1 . As shown in FIG. 2A, the motor  29  comprises a cylindrical DC motor  30  and an eccentric weight  31  integrally fixed to a rotary shaft  30   a  of the motor  30 . The eccentric weight  31  has an asymmetric shape with respect to the rotary shaft  30   a . The eccentric weight  31  also has a center of gravity (center of mass) G misaligned from an axial center of the rotary shaft  30   a.    
     The motor  29 , which is installed in the housing  1   a , has a motor housing, i.e. a stator of the motor  30  attached integrally with the housing  1   a . The driving unit  28  supplies a drive control signal to the motor  29  in response to an incoming call to drive the motor  29 . 
     FIGS. 3A and 3B are diagrams showing waveform examples of the drive control signal to drive the motor  29  in response to an incoming call. FIG. 3A shows a waveform in the case where a control signal for the forward rotation of the motor  29  and a control signal for the reverse rotation are alternately repeatedly applied at the same rotating period. 
     FIG. 3B shows another waveform in the case where the control signal for the forward rotation and the control signal for the reverse rotation are alternately applied at the same rotating period, and the rotating period is repetitively changed at a predetermined period with respect to the time. 
     The driving unit  28  supplies the drive control signal to the motor  29  to drive a rotor  30  of the motor including the rotary shaft  30   a  integral with the eccentric weight  31 , thereby repeating the forward rotation and the reverse rotation of the motor and the weight. The stator receives the vibration caused by those rotations to vibrate together with the housing  1   a , which causes the cellular phone  1  to vibrate to inform the user of the incoming call. 
     A vibration of the cellular phone  1  in response to an incoming call will now be described in detail. Explanation will be made on the assumption that the cellular phone  1  with a vibrator for informing a user of an incoming call is activated and is left on a horizontal table, and receives an incoming call. 
     FIGS. 4A-4D are vertical sectional views showing the motor  29  attached in the housing  1   a . The cellular phone  1  is placed on a table. As positioned, the center of gravity G of the eccentric weight  31  moves about its rotary shaft  30   a  in accordance with the rotation of the motor  29 . 
     FIGS. 4A-4D sequentially show positions of the center of gravity G of the eccentric weight  31  for every 90° change about the rotary shaft  30   a  when the motor  29  rotates in the direction shown by an arrow (solid line; forward rotation) once. When the eccentric weight  31  rotates in one direction around the rotary shaft  30   a  as mentioned above, each state of FIGS. 4A-4D is repeated every 90° of rotation. As angular velocity of the rotation is gradually increasing, a centrifugal force applied to the rotary shaft  30   a  gradually increases. Therefore, the housing la having the motor  29  attached thereto receives the force. 
     In FIG. 4A, the housing  1   a  receives a vertically upward force with respect to the table surface. In FIG. 4B, the housing  1   a  receives a horizontal right-direction force with respect to the table surface. In FIG. 4C, the housing  1   a  receives a vertically downward force with respect to the table surface. In FIG. 4D, the housing  1   a  receives a horizontal left-direction force with respect to the table surface. 
     That is, by repeating the states of FIGS. 4A and 4C every rotation of the rotary shaft  30   a , the housing  1   a  repetitively receives the vertically upward/downward force with respect to the table surface. By repeating the states of FIGS. 4B and 4D, the housing  1   a  repetitively receives the force in the horizontal right/left directions with respect to the table surface. The housing  1   a  on the table alternately repeats the upward movement with respect to the table and the horizontal directions movement to vibrate itself every rotation of the motor. 
     In the motor  29 , the rotor rotates due to the magnetic interaction between the stator and the rotor, and the stator receives its reaction force. When the rotor forwardly rotates, the stator receives the opposite force (which has a direction of an arrow shown by a broken line in FIGS.  4 A- 4 D). The housing  1   a  to which the stator of the motor is attached, consequently, receives the force in the direction opposite to the rotating direction of the rotary shaft  30   a  about the rotary shaft  30   a.    
     FIGS. 5A-5B are schematic views of the housing  1   a  of the cellular phone  1  receiving the force during the period in which the motor  29  is rotating in one direction. FIG. 5A shows the motor  29  rotating forwardly. FIG. 5B shows the motor  29  rotating reversely. 
     As mentioned above, when the rotary shaft  30   a  rotates forwardly, the housing  1   a  alternately repeats the upward movements with respect to the table and the horizontal-direction movements every rotation of the rotary shaft  30   a  due to the force caused by the rotation of the eccentric weight  31 , thereby vibrating itself. At the same time, the housing  1   a  also receives the force in the direction opposite to the rotating direction of the eccentric weight  31  about the rotary shaft  30   a . As shown in FIG. 5A, therefore, the housing  1   a  moves in the horizontal left direction, vibrating in the upper/lower and right/left directions on the table surface. 
     When the rotary shaft  30   a  reversely rotates, the housing  1   a  alternately repeats the upward movement with respect to the table and the horizontal-direction movement to vibrate every rotation of the rotary shaft  30   a  due to the force caused by the rotation of the eccentric weight  31 . At the same time, the housing  1   a  also receives the force in the direction opposite to the rotating direction of the eccentric weight  31  about the rotary shaft  30   a . As shown in FIG. 5B, therefore, the housing  1   a  moves in the horizontal-right direction while vibrating in the upper/lower and right/left directions on the table surface. 
     Described above, the driving unit  28  in a cellular phone  1  provided with an activated vibrator drives the motor  29  in accordance with a command from the CPU  23  in response to an incoming call to rotate the rotor of the motor  30  in the forward direction and the reverse direction alternately. Consequently, the vibration occurring due to the rotations causes the stator to vibrate together with the housing  1   a , so that the cellular phone  1  vibrates and informs the holder or user of the phone of the incoming call. 
     The rotor of the motor and the integral eccentric weight  31  repeat the forward rotation and the reverse rotation. Therefore, even if the cellular phone  1  is left on a table when receiving an incoming call, the cellular phone repeats the reciprocation in the horizontal right/left directions on the table about the rotary shaft  30   a  while vibrating itself. By properly setting the periods of the forward rotation and the reverse rotation, the cellular phone move only within a predetermined area from the position in which it is originally left. 
     In the above embodiment, the CPU  23  supplies the drive control signal to control the driving unit  28  in response to an incoming call and notifies the holder or user of the incoming call. It should be noted that the apparatus according to the invention is not limited to that shown in the diagram. It is within the scope of the invention to provide an apparatus of the present invention including a timer for informing a predetermined state such as a preset time. 
     It is understood that the foregoing description and accompanying drawings set forth the preferred embodiments of the invention at the present time. Various modifications, additions and alternative designs will, of course, become apparent to those skilled in the art in light of the foregoing teachings without departing from the spirit and scope of the disclosed invention. Thus, it should be appreciated that the invention is not limited to the disclosed embodiments but may be practiced within the full scope of the appended claims.