Abstract:
An electronic control device for controlling a controlled device installed on a bicycle comprises a programmed computer that controls the control device. A reset circuit receives information related to a traveling condition of the bicycle and provides a reset signal to the computer in response to the occurrence of a predetermined traveling condition.

Description:
BACKGROUND OF INVENTION 
   The present invention is directed to bicycles and, more particularly, to electronic control devices for bicycles. 
   Recently, some bicycles have been equipped with electronic control devices that have built-in computer chips. Examples of such control devices include devices for automatically shifting gearshift devices depending on bicycle speed, and devices for controlling display devices that display bicycle speed, travel distance, and the like. 
   Sometimes a programmed microprocessor may experience a system error due to electrical noise or some other disturbance, or to a programming bug or the like, thus causing the program to enter the wrong routine and causing the gearshift devices and/or display devices to malfunction, for example. Some electronic control devices are equipped with a reset switch to return the microprocessor to the appropriate routine. Conventional reset switches include those disposed inside the control device but visible through a round access hole, typically about 2 mm in diameter, wherein reset switch is pressed using the tip of a ballpoint pen or some other pointed object. Operating the reset switch sends a reset signal to the reset terminal of the microprocessor, and the microprocessor resets accordingly. 
   Since a bicycle typically is used outdoors, such a reset switch creates the risk of water and dust entering the access hole and into the control device. Also, since the access hole is relatively small, it is not possible to perform the reset operation if no pointed object for performing the reset operation is readily available, thus creating great inconvenience to the rider. 
   Some devices address such problems by eliminating the manually operated reset switch entirely. In these devices, it is necessary to carry out the reset operation by interrupting the power supply, such as by disconnecting a battery used as the power supply. However, this requires a substantial amount of work by the rider, thus also creating great inconvenience to the rider. 
   SUMMARY OF INVENTION 
   The present invention is directed to various features of a bicycle control device that has a reset function. In one embodiment, an electronic control device for controlling a controlled device installed on a bicycle comprises a programmed computer that controls the control device. A reset circuit that receives information related to a traveling condition of the bicycle provides a reset signal to the computer in response to the occurrence of a predetermined traveling condition. Additional inventive features will become apparent from the description below, and such features alone or in combination with the above features may form the basis of further inventions as recited in the claims and their equivalents. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a side view of a particular embodiment of a bicycle; 
       FIG. 2  illustrates connections among an internal hub transmission, a shift control unit, and a hub dynamo; 
       FIG. 3  is a side view of components in the shift control unit; 
       FIG. 4  is a top view of components in the shift control unit; 
       FIG. 5  is a more detailed view of a shift controller mounted to the handlebar; 
       FIG. 6  is a schematic block diagram of the electronic components of the shift control unit; 
       FIG. 7  is a block diagram of a particular embodiment of a control element with a reset function; and 
       FIGS. 8–11  are block diagrams of additional embodiments of a control element with a reset function. 
   

   DETAILED DESCRIPTION 
     FIG. 1  is a side view of a particular embodiment of a bicycle. This bicycle is a recreational bicycle comprising a frame  1  having a double-loop frame body  2  formed from welded tubes, a front fork  3  mounted to the frame body  2  for rotation around a diagonal axis, a handlebar component  4 , a drive component  5 , a front wheel  6  on which a dynamo hub  8  with brakes is mounted, a rear wheel  7  on which an internal shifting hub  10  is mounted, a saddle  11 , a shift control unit  12  to control shifting of the internal shifting hub  10 , and a shift controller  20  for manually operating the shift control unit  12 . 
   The handlebar component  4  comprises a handle stem  14 , fastened to the upper part of the front fork  3 , and a handlebar  15  fastened to the handle stem  14 . Brake levers  16  and grips  17  are mounted on both ends of the handlebar  15 . In this embodiment, the shift controller  20  is integrated with the right-side brake lever  16 . The drive component  5  comprises a crank  37 , mounted on the lower part (bottom bracket component) of the frame body  2 , and a chain  38  that engages the crank  37  and the internal shifting hub  10 . The internal shifting hub  10  is capable of producing three speed steps, including a low speed step (speed 1), an intermediate speed step (speed 2), and a high speed step (speed 3). These three speed steps can be selected by means of a motor unit  29  ( FIG. 3 ) in the shift control unit  12 . The dynamo hub  8  of the front wheel  6  can be fitted with a roller-type front brake, and it houses an alternating current dynamo  19  ( FIG. 6 ) that generates electricity in response to the rotation of the front wheel  6 . As shown in  FIG. 2 , the shift control unit  12  is electrically connected to the alternating current dynamo  19  housed in the dynamo hub  8  by electrical wiring  40 , and it is electrically connected to the shift controller  20  by electrical wiring  41 . The shift control unit  12  is mechanically connected to the internal shifting hub  10  by a shift control cable  42 . 
   As shown in  FIGS. 3 and 4 , the shift control unit  12  comprises  a lamp case  13  mounted to a lamp stay  3   a  located midway along the front fork  3  for housing a lamp  18 . The motor unit  29  and a circuit unit  30  are housed in the lamp case  13 . The motor unit  29  comprises an electric shifting motor  45 , a cable operating component  46  which moves into three shifting positions by means of the shifting motor  45 , and a position sensor  47  ( FIG. 6 ) to detect the shift position of the cable operating component  46 . One end of the shift control cable  42  is connected to cable operating component  46 . The circuit unit  30  comprises a control element  25  ( FIG. 6 ) containing a microprocessor  50  ( FIG. 7 ) comprising a CPU, RAM, ROM, and an I/O interface. 
   As shown in  FIG. 5 , the shift controller  20  comprises two operating buttons  21  and  22  in the form of triangular pushbuttons disposed next to each other, an operating dial  23  disposed above the operating buttons  21  and  22 , and a liquid crystal display device  24  disposed to the left of the operating dial  23 . The operating button  21  on the left side may be used for manually shifting from the low speed step to the intermediate speed step and to the high speed step. The operating button  22  on the right side may be used for manually shifting from the high speed step to the intermediate speed step and to the low speed step. The operating buttons  21  and  22  also may be used to lock the internal shifting hub  10  in the low speed step regardless of bicycle speed, or to limit the operation of the internal shifting hub  10  to the upper or lower two adjacent speed steps. 
   The operating dial  23  is used for switching between eight automatic shifting modes (A 1 –A 8 ) using eight detent positions. The eight automatic shifting modes (A 1 –A 8 ) are modes for automatically shifting the internal shifting hub  10  according to a bicycle speed signal derived from the alternating current dynamo  19 . The eight automatic shifting modes (A 1 –A 8 ) are designed to allow the rider to set shift timing (i.e., the threshold speed values at which shifting will occur) for upshifting (shifting from low speed to high speed) and downshifting (shifting from high speed to low speed) according to the rider&#39;s desire and physical capability. 
     FIG. 6  is a block diagram illustrating the structure of the overall bicycle control system. Heavy lines in  FIG. 6  indicate lines carrying about 1 A of current, solid lines indicate lines carrying about 5 mA of current, and dotted lines indicate signal lines. Control element  25  is operatively coupled to an operating switch  26  (which schematically represents the operating dial  23  and operating buttons  21  and  22  in the shift controller  20 ); to the liquid crystal display device  24 ; to a motor driver  28 ; to a power storage element  32 ; to a charge control circuit  33 ; to a dynamo waveform shaping circuit  34  that generates a speed signal derived from the output of the alternating current dynamo  19 ; to an auto light circuit  35  to the light sensor  36  (illumination sensor) for controlling the operation of lamp  18 ; to the position sensor  47  of the motor unit  29 , and to other input/output components. 
   Control element  25  includes a programmed microprocessor  50  ( FIG. 7 ) that automatically controls shifting of the internal shifting hub  10  via motor driver  28  and motor unit  29  according to travel speed, and it controls the information (e.g., bicycle speed and speed step) displayed on the liquid crystal display device  24  disposed in the shift controller  20 . Motor driver  28  operates on a 1 mA current supplied by the power-storage element  32 , and it controls a 1 A current supplied by the power storage element  32  to operate the shifting motor  45 . In this embodiment, liquid crystal display  24  has a microprocessor (not shown) separate from the microprocessor  50  of the control element  25 , and that microprocessor is designed to carry out display control on the basis of information from control element  25 . 
   Control element  25  also controls lamp  18  through auto light circuit  35  by turning lamp  18  on when surrounding light conditions fall below a certain prescribed brightness, and by turning lamp  18  off when surrounding light conditions are above the prescribed brightness. More specifically, auto light circuit  35  supplies or interrupts the 1A current output from the alternating current dynamo  19  to the lamp  18  in response to on/off signal output from control element  25 . Control element  25  generates these signal based on the signals from the light sensor  36  in such a manner that lamp  18  is switched on automatically when light levels fall below a prescribed limit, and lamp  18  is switched off when light levels exceed the prescribed limit. 
   The charge control circuit  33  comprises, for example, a half-wave rectifier circuit that rectifies an alternating current output from the alternating current dynamo  19  to a direct current that supplies power storage element  32 . The power storage element  32  may comprise, for example, a high-capacity capacitor that stores the direct current power that is output from the charg control circuit  33 . The power storage element  32  also may comprise secondary batteries such as nickel cadmium batteries, lithium ion batteries, nickel-metal hydride batteries, etc., in lieu of a capacitor. 
   Battery replacement and recharging are unnecessary because the power storage element  32  stores electrical power from the alternating current dynamo  19 , and components such as the control element  25  are operated using this electrical power. Monitoring remaining battery power and carrying along spare batteries also become unnecessary, and shifting can be done automatically without performing the cumbersome procedures required by conventional power sources. The electrical power from the alternating current dynamo  19 , which conventionally is not employed in the daytime, can be put to effective use in the shift control unit  12 . 
   The dynamo waveform shaping circuit  34  forms a speed signal from the alternating current output from the alternating current dynamo  19 . More specifically, a half-cycle is extracted from a sine wave alternating current signal, passed through a Schmitt circuit or other appropriate waveform shaping circuit, and formed into a pulse signal corresponding to speed. Control element  25  uses this signal to control the automatic shifting of the internal shifting hub  10  without requiring a separate speed sensor. 
   Because alternating current dynamos generally have a plurality of circumferentially disposed magnetic poles, the alternating current dynamo outputs an alternating current signal with a frequency related to the bicycle speed and the number of magnetic poles. Consequently, it is possible to obtain a larger number of signal pulses from the alternating current signal during each wheel rotation in comparison with a speed signal obtainable, for example, from a conventional speed sensor that detects a magnet mounted to the bicycle wheel. Therefore, the bicycle speed can be accurately detected within the space of one wheel rotation, and shifting can be controlled in real time with high precision. Furthermore, since shifting is controlled based on the alternating current signal from the alternating current dynamo  19 , it is no longer necessary to dispose the shift control unit  12  in the vicinity of the bicycle wheel. No limitation is placed on the mounting position of the shift control unit  12 . 
   As shown in  FIG. 7 , in this embodiment control element  25  includes a frequency sensing circuit  52  connected to the alternating current generator  19  and to a reset terminal R of microprocessor  50 . Frequency sensing circuit  52  senses the frequency of the alternating current signal output by alternating current generator  19 . When the frequency satisfies a certain predetermined condition (e.g., when the frequency falls below a predetermined frequency level such as 5 Hz), a High signal that is normally output to microprocessor  50  changes to a Low signal. Microprocessor  50  is designed to reset when a Low signal is input to reset terminal R. As a result, microprocessor  50  resets when the frequency of alternating current generator  19  falls below a predetermined level (i.e., when bicycle speed falls below a predetermined level). Thus, if microprocessor  50  encounters a system error, it will perform a reset operation without the need for a manual reset procedure that imposes a burden on the rider. 
   In this embodiment, microprocessor  50  is reset when the frequency of the signal output by alternating current generator  19  falls below a predetermined level. However, it should be understood that microprocessor  50  may be reset upon the occurrence of any travel condition of the bicycle or rider. For example,  FIG. 8  shows an embodiment wherein a voltage sensing circuit  152  is connected to the alternating current generator  19  and to the reset terminal R of microprocessor  50 . Voltage sensing circuit  152  could comprise, for example, an ordinary smoothing circuit employing a capacitor and diode series-connected with a Schmitt trigger circuit. When the output voltage of alternating current generator  19  meets a certain predetermined condition (e.g., when the output voltage falls below a predetermined voltage such as 2 volts), a High signal that is normally output to microprocessor  50  changes to a Low signal. Since microprocessor  50  is designed to reset when a Low signal is input to reset terminal R, microprocessor  50  resets when the voltage of alternating current generator  19  falls below the predetermined level (i.e., when bicycle speed falls below a predetermined level). 
     FIG. 9  is a block diagram of another embodiment of a control element  25  with a reset function. In this embodiment, microprocessor  50  may be connected to a non-volatile memory such as an EEPROM  53 . Various operating information may be stored in EEPROM  53  prior to reset, and the stored information may be returned to the microprocessor  50  after the reset operation has completed. More specifically, in this embodiment a voltage sensing circuit  252  is connected to the reset terminal R of microprocessor  50  and also to an input/output (I/O) terminal of microprocessor  50 . When a certain predetermined condition is met (e.g., when the voltage of alternating current generator  19  falls below a predetermined level), voltage sensing circuit  252  outputs a reset warning signal to the I/O terminal of microprocessor  50 . Upon receiving the reset warning signal, microprocessor  50  stores in EEPROM  53  certain data currently stored in RAM (such as cumulative distance traveled, maximum speed data, current shift position, various display data, data for the selected shift mode, etc.). After outputting the reset warning signal, voltage sensing circuit  252  waits for a time interval sufficient for the required information to be stored in EEPROM  53  (e.g., 2 seconds), and then changes the High signal normally output to the reset terminal R of microprocessor  50  into a Low signal. Since microprocessor  50  is designed to reset when a Low signal is input to reset terminal R, microprocessor  50  resets when the voltage of alternating current generator  19  falls below the predetermined level (i.e., when bicycle speed falls below a predetermined level). When the microprocessor  50  initializes after reset, the contents of EEPROM  53  are read out and placed in the RAM of microprocessor  50 . As a result, it is possible to save information that ordinarily would be lost during reset, and the bicycle operation may resume smoothly subsequent to reset. 
   In the above embodiments, a reset signal is output directly to microprocessor  50  by a reset circuit such as a frequency sensing circuit  52  or a voltage sensing circuit  152  or  252  once a predetermined condition has been met. Alternatively, as shown in  FIG. 10 , a reset circuit  55  may comprise a voltage sensing circuit  352  and a reset integrated circuit (IC)  51 , wherein voltage sensing circuit  352  may function as a reset activating circuit, and reset IC  51  may function as a separate reset signal output circuit. In this embodiment, reset IC  51  outputs a reset signal to microprocessor  50  when voltage sensing circuit  352  interrupts power to reset IC  51 . 
   In this embodiment, voltage sensing circuit  352  has a power switch  352   a  connected to power storage element  32 , to reset IC  51  and to a power supply terminal Vcc of microprocessor  50 . In the presence of a predetermined condition like those described previously, power switch  352   a  interrupts the supply of power to reset IC  51  and to the power supply terminal Vcc of microprocessor  50 , and a reset signal is output to microprocessor  50  by reset IC  51 . Once the predetermined condition is no longer met (e.g., the bicycle begins to move at speed faster than a predetermined level), power switch  352   a  turns on power to reset IC  51  and microprocessor  50 , and microprocessor  50  is reset. Thus, microprocessor  50  may resume normal operation once the power level has stabilized. 
     FIG. 11 , is a block diagram of another embodiment of a control element  25  similar to the embodiment shown in  FIG. 10 , wherein features similar to that shown in  FIG. 9  are added. As shown in  FIG. 11 , reset IC  51  and EEPROM  53  are connected to microprocessor  50 , and a voltage sensing circuit  452  has a power switch  452   a  connected to power storage element  32 , to reset IC  51  and to the power supply terminal Vcc of microprocessor  50 . Voltage sensing circuit  452  also is connected to the I/O terminal of microprocessor  50  to provide a reset warning signal to microprocessor  50 . 
   When a predetermined condition is met, voltage sensing circuit  452  outputs a reset warning signal to the I/O terminal of microprocessor  50 . Information to be saved then is output from RAM in microprocessor  50  to EEPROM  53 , where it is stored. After a predetermined time interval, power switch  452   a  turns off power to reset IC  51  and microprocessor  50 , and a reset signal is output to microprocessor  50  by reset IC  51 . Once the predetermined condition is no longer met (e.g., the bicycle begins to move at speed faster than a predetermined level), power switch  452   a  turns on power to reset IC  51  and microprocessor  50 , and microprocessor  50  is reset. Thus, microprocessor  50  may resume normal operation once the power level has stabilized. 
   While the above is a description of various embodiments of inventive features, further modifications may be employed without departing from the spirit and scope of the present invention. For example, the frequency and voltage values of the predetermined conditions disclosed in the above embodiments are merely exemplary, and the invention is not limited to these parameters. In the above embodiments, a predetermined condition is determined to have been met when voltage or frequency passes a predetermined level, but instead a predetermined condition could be determined to have been met when voltage or frequency passes a predetermined level for a predetermined time interval. 
   In the above embodiments, it is determined from alternating current generator voltage or frequency that the travel information satisfies a predetermined condition, but a predetermined condition could be ascertained from various sensors such as a wheel speed sensor or a crank rotation sensor. Also, while a control device directed to a bicycle gearshift device was described, inventive features also would be found by applying the teachings herein to control devices for controlling other controlled devices, such as a display device or a suspension device. 
   Power from an alternating current generator  19  disposed in a dynamo hub  8  having good generating efficiency and low travel resistance was described in the above embodiments, but an alternating current generator that generates power through contact with the wheel rim or tire could be used. An ordinary secondary cell also could be used to supply power. 
   The size, shape, location or orientation of the various components may be changed as desired. Components that are shown directly connected or contacting each other may have intermediate structures disposed between them. The functions of one element may be performed by two, and vice versa (e.g., reset IC  51  was a separate chip from microprocessor  50  in the disclosed embodiments, but alternatively these could be placed on a single chip). The structures and functions of one embodiment may be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the scope of the invention should not be limited by the specific structures disclosed or the apparent initial focus or emphasis on a particular structure or feature.