Abstract:
A bicycle display apparatus comprises a display unit and a color changing mechanism. The display unit optically displays information corresponding to the characteristic of the bicycling environment, and it includes a background light or a photoemission element that facilitates easy viewing of the displayed information. The color attribute changing mechanism changes at least one of the color, hue, color saturation and brightness of the background light in accordance with the characteristic of the bicycling environment.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention is directed to bicycles and, more particularly, to various features of a bicycle display apparatus that displays various characteristics of a bicycling environment.  
           [0002]    Bicycle computers, often termed cycle computer, ordinarily includes a display that typically displays information regarding the bicycle&#39;s state of motion, such as bicycle speed or crank rotation speed (cadence). In order to display such information, the display often includes light-emitting elements such as light-emitting diodes (LED&#39;s) and/or a backlit liquid crystal display elements. Turning ON the power switch or some other switch activates the LED&#39;s and/or the backlit crystal display elements.  
           [0003]    In recent years, there has been a rising demand for an increase in the amount of information that can be displayed on a typical bicycle computer. For example, it has been desired to display, in addition to speed and cadence information, information on the state of motion of the bicycle, such as the total distance traveled, information on the state of the bicycle itself, such as the current transmission gear position, and information related to the bicycling environment, such as the time of day. In the case of LED&#39;s, displaying such information requires an increase in the number of LED&#39;s and assigning particular meanings to the areas illuminated. Similarly, in the case of a liquid crystal display device, displaying such information requires an increase in the amount of light permeable and non-light permeable areas and assigning particular meanings to the added areas. In either case, information on the display is displayed by alternating between two display states, i.e., the ON and OFF states of the individual elements of the LED&#39;s or the light-permeable and non-light-permeable elements of liquid crystal displays, thus complicating construction.  
           [0004]    Where a large amount of information is to be displayed, the problem exists that the display cannot handle a sufficient amount of information, thus making the display uninteresting or making the information difficult to intuitively understand. Moreover, since the area of the display for a bicycle is limited by such factors as the capacity of the power supply and the size of the display, the information displayed becomes small and even more difficult to intuitively understand when a large amount of information is to be displayed in such a limited area  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention is directed to inventive features of a bicycle display apparatus. In one embodiment, a bicycle display apparatus comprises a display unit and a color changing mechanism. The display unit optically displays information corresponding to the characteristic of the bicycling environment, and it includes a background light that facilitates easy viewing of the displayed information. The color attribute changing mechanism changes at least one of the color, hue, color saturation and brightness of the background light in accordance with the characteristic of the bicycling environment.  
           [0006]    In another embodiment, a bicycle display apparatus comprises a display unit and a color changing mechanism. The display unit optically displays information corresponding to the characteristic of the bicycling environment, and it includes at least one photoemission element that displays the desired information. The color attribute changing mechanism changes at least one of the color, hue, color saturation and brightness of the at least one photoemission element in accordance with the characteristic of the bicycling environment.  
           [0007]    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 THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a side view of a bicycle that includes a particular embodiment of a display apparatus;  
         [0009]    [0009]FIG. 2 is a detailed view of particular embodiments of handlebar mounted components of the bicycle shown in FIG. 1;  
         [0010]    [0010]FIG. 3 is a block diagram of a particular embodiment of electrical components used with the display;  
         [0011]    [0011]FIG. 4 is a cross sectional view of a case surrounding a control apparatus;  
         [0012]    [0012]FIG. 5 is a plan view showing the display contents of an embodiment of a liquid crystal display screen;  
         [0013]    [0013]FIG. 6 is a flow chart showing a particular embodiment of a main routine executed by the control apparatus;  
         [0014]    [0014]FIG. 7 is a flow chart showing a particular embodiment of a control routine executed by the control apparatus;  
         [0015]    [0015]FIG. 8 is a circuit diagram showing a particular embodiment of an LED drive circuit of a second embodiment of a display;  
         [0016]    [0016]FIG. 9 is a timing chart showing a particular embodiment of drive timing of the LED&#39;s shown in FIG. 8; and  
         [0017]    [0017]FIG. 10 is a plan view of the display contents of the second embodiment. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0018]    [0018]FIG. 1 is a side view of a bicycle that includes a particular embodiment of a bicycle display. The bicycle  1  is a sport bicycle of a mountain bike type, and it comprises a frame  2 , a front fork  3  rotatably mounted to frame  2  in a slanted manner, a handlebar assembly  4  mounted to the upper part of fork  3 , a front wheel  5  rotatably attached to the lower part of fork  3 , a rear wheel  6  rotatably attached to the rear of frame  2 , a chain  7 , a front external gear shift transmission  8 , a rear external gear shift transmission  9 , and a saddle  11  on which the rider sits. A front wheel brake  16  is provided for braking the front wheel  5 , and a rear wheel brake  17  is provided for braking the rear wheel  6 . As shown in FIG. 2, respective grips  12   a ,  12   b  and brake levers  13   a ,  13   b  are provided on both ends of handlebar assembly  4 . Brake lever  13   b  is connected to the front wheel brake  16  for braking front wheel  5 , and brake lever  13   a  is connected to the rear wheel brake  17  for braking rear wheel  6 .  
         [0019]    The front external gear shift transmission  8  is a mechanical unit attached in the central lower part of frame  2  for transmitting the drive force generated by the rider to the rear external gear shift transmission  9  via the chain  7 . In this embodiment, the front external gear shift transmission  8  comprises three sprockets  37  of various sizes, and a front derailleur  33 . The three sprockets  37  are installed on a gear crank  31  that is rotated when the rider pushes pedals  32   a  and  32   b . The gear crank  31  comprises a crankshaft  34  that passes horizontally and rotatably through the central lower part of frame  2 , a right crank  35 , and a left crank  36 . One end of the right crank  35  is nonrotatably connected to the right side of crankshaft  34 , and the three sprockets  37  are nonrotatably attached to the right crank  35 . One end of the left crank  36  is nonrotatably connected to the left side of crankshaft  34 . The other ends of right crank  35  and left crank  36  rotatably support pedals  32   a  and  32   b , respectively. The front derailleur  33  engages the chain  7  with one of the three sprockets  37  and can be moved by a motor, solenoid, or some other actuator (not shown in the figures) that is controlled by a control apparatus  15  described below. A front derailleur position sensor (not shown in the figures) detects the position of front derailleur  33 , and hence the current gear of front transmission  8 .  
         [0020]    The rear external gear shift transmission  9  serves to transmit the driving force transmitted by the chain  7  to the rear wheel  6 . The rear external gear shift transmission  9  comprises a rear sprocket wheel  41  and a rear derailleur  42 . In this embodiment, rear sprocket wheel  41  comprises seven sprockets  43  of different sizes that are mounted concentrically with the hub portion of rear wheel  6 . Rear derailleur  42  engages chain  7  with one of the seven sprockets  43  and can be moved by a motor, solenoid, or some other actuator (not shown in the figures) that is controlled by a control apparatus  15 . A rear derailleur position sensor (not shown in the figures) detects the position of rear derailleur  42  and hence the current gear of rear external gear shift transmission  9 .  
         [0021]    As shown in FIG. 2, shift command units  14   a ,  14   b  are provided on alternate sides of handlebar assembly  4  inwardly of grips  12   a ,  12   b  and brake levers  13   a ,  13   b , respectively. A control apparatus  15 , described below, is attached to the central portion of handlebar assembly  4 , and it is operatively connected to the shift command units  14   a ,  14   b . A generator hub  49  that forms a part of the front wheel  5  provides operating power to a lamp  50  mounted to frame  2  as well as speed signals to control apparatus  15 .  
         [0022]    The shift command units  14   a ,  14   b  are used primarily for manually shifting the front external gear shift transmission  8  and the rear external gear shift transmission  9 . A front upshift button  18   a  and a front downshift button  19   a  are provided in the shift command unit  14   a , and a rear upshift button  18   b  and a rear downshift button  19   b  are provided in the shift command unit  14   b . In this embodiment, the upshift buttons  18   a  and  18   b  provide signals for upshifting the front and rear external gear shift transmissions  8  and  9  by one speed step. Similarly, the downshift buttons  19   a  and  19   b  provide signals for downshifting the front and rear external gear shift transmissions  8  and  9  by one speed step.  
         [0023]    Right and left mode buttons  20   a  and  20   b  are disposed on the shift command units  14   a  and  14   b , respectively. The mode buttons  20   a  and  20   b  are used to alternate the display on the display unit  24  of the control apparatus  15  and to input default values, for example. By operating these mode buttons  20   a  and  20   b , the rider can operate the display unit  24  without removing his or her hands from the riding positions on the handlebar assembly  4 .  
         [0024]    As shown in FIG. 3, the control apparatus  15  includes a controller  23  comprising a CPU  21  and a memory  22 , a display unit  24  that has a liquid crystal display screen  25  that uses the segment method and displays various types of information such as the current gear, the bicycle speed and so on, a backlight  26  that illuminates the liquid crystal display screen  25  from the rear surface thereof, and a clock  48 . The controller  23  controls the control apparatus  15  via the CPU  21  in accordance with the contents of the memory  22 . The upshift and downshift buttons  18   a ,  18   b ,  19   a  and  19   b , the right-hand and left-hand mode buttons  20   a  and  20   b , the front lamp  50  and the generator hub  49  also are connected to the controller  23 . An illuminance sensor (not shown) is disposed on the front lamp  50 , and the front lamp  50  turns ON and OFF in accordance with the illuminance level of the surrounding environment. The illuminance signals from the illuminance sensor are also sent to the controller  23 . The generator hub  49  sends wheel rotation signals to the controller  23  as noted above, and the clock  48  has a calendar function and can generate date and time data. Control apparatus  15  is connected to the actuators for front derailleur  33  and rear derailleur  42  via a connector  28 , and it performs gear shift control for both mechanisms. In the case of manual gear shift mode, such control is executed in response to the manual operation of shift command units  14   a  and  14   b.    
         [0025]    The control apparatus  15  is disposed in a box-shaped control case  27 , and the display unit  24  is disposed on the top surface thereof. The case  27  is detachably mounted to the bracket  29  that is mounted to the handlebar assembly  4  of the bicycle  1 . A display window  27   a  made of clear synthetic resin is disposed on the surface of the case  27 , as shown in FIG. 4. The liquid crystal display screen  25  is disposed at a position facing the display window  27   a . The backlight  26  is disposed on the back of the liquid crystal display screen  25 . The backlight  26  has a light-emitting unit  26   a  composed of red, green and blue light-emitting diodes (LED&#39;s) and a light-guide plate  26   b  that is disposed at one end of the light-emitting unit  26   a  and diffuses the light output from the light-emitting unit  26   a  over the entire surface of the liquid crystal display screen  25 . A pair of manually-operated mode buttons (not shown in the figures) having the same function as the right-hand and left-hand mode buttons  20   a  and  20   b  are disposed on the back surface of the case  27 . As a result, the display unit  24  can be configured to perform various display functions even when the case  27  is detached from the bracket  29 .  
         [0026]    Control apparatus  15  measures or calculates and then displays various types of information such as the speed of the bicycle, cadence, distance traveled, lap times, the gear positions of the external gear shift mechanisms and the like, and it displays the information on the liquid crystal display screen  25  of the display unit  24 . The liquid crystal display screen  25  is disposed at a position that is easy for the rider to see, such as near the central reference plane of the bicycle, i.e., in the middle of the handlebar assembly  4 .  
         [0027]    [0027]FIG. 5 shows an embodiment of display contents of a liquid crystal display screen  25 . A primary numerical display  52 , a secondary numerical display  53 , a contents display  54 , a number of rear gears display  55  and a number of front gears display  56  are disposed on the display screen  51 . Such information as the bicycle speed and time are displayed numerically in the primary numerical display  52  and the secondary numerical display  53 . The contents display  54  indicates the contents displayed in the primary numerical display  52  and the secondary numerical display  53 , and also displays the gear shift mode. For example, ‘VEL’ means the bicycle&#39;s traveling speed, ‘DST’ means the distance traveled or the total distance, ‘CLK’ means the clock, ‘TIM’ means the amount of time traveled, and ‘GEA’ means the shift position of the chain gear mechanism. In addition, ‘AT’ means that the current gear shift mode is automatic shift mode, while ‘MT’ means that the current gear shift mode is manual shift mode.  
         [0028]    The units of speed can be switched between ‘Km/h’ and ‘Mile/h’, and the units of distance can be switched between ‘Km’ and ‘Mile’. When the units of distance are set during initialization of the display unit  24 , the units of distance thus set are used in the display on the display screen  51 .  
         [0029]    The number of rear gears display  55  displays the number of gears in the rear external gear shift mechanism  9 . The number of rear gears display  55  consists of a sequence of oval display symbols aligned in decreasing order of size from left to right. These symbols are arranged so as to correspond to the effective diameters of the gears of the rear gear shift mechanism  9 . During initialization of the display unit  24 , the numbers of gears for the front and rear external gear shift mechanisms  8  and  9  are set on the display to match the actual numbers of gears on the bicycle. For example, if the number of rear gears is set to seven, the number of rear gears display  55  displays seven of the oval plate-shaped symbols from the left, and the rightmost two symbols are not displayed.  
         [0030]    The number of front gears display  56  displays the number of gears of the front external gear shift mechanism  8 . The number of front gears display  56  consists of a sequence of oval display symbols aligned in decreasing order of size from right to left. During initialization, if the number of front gears is set to two, the number of front gears display  56  displays two of the oval display symbols from the right, and the leftmost symbol is not displayed. Because the number of rear gears display  55  and number of front gears display  56  are arranged such that the oval display symbols correspond to the gear arrangements of the actual gear shift mechanisms  8  and  9  of the bicycle as described above, and such oval display symbols vary in size, the number of gears available can be understood intuitively at a glance.  
         [0031]    An example of the display control executed by the controller  23  will now be described with reference to the control flow chart shown in FIGS. 6 and 7. When power supply is begun through the installation of a battery or the like in the control apparatus  15 , initialization is performed in step S 1 . In this example, the gear shift controller  15  is set such that the primary numerical display  52  and the secondary numerical display  53  display the bicycle speed and the current time, respectively, during initialization. In step S 2 , the display routine described below with reference to FIG. 7 is executed. In step S 3 , it is determined whether or not key input using the right-hand and left-hand mode buttons  20   a  and  20   b  has been carried out. In step S 4 , it is determined whether or not manual gear shift mode has been selected. In step S 5 , it is determined whether or not automatic gear shift mode has been selected. In step S 6 , it is determined whether or not a different instruction has been input. If the determination in step S 6  is ‘No’, the controller  23  returns to step S 2 .  
         [0032]    If it is determined in step S 21  that the current time is between 6 a.m. and 4 p.m. If it is determined that the current time falls within that range, i.e., that it is daytime, then the controller  23  proceeds to step S 22 . In step S 22 , it is determined from the output from the illuminance sensor mounted to the front lamp  50  whether or not the front lamp  50  is ON. If the lamp  50  is already ON, the controller  23  proceeds to step S 23  and the backlight  26  is set to orange. Specifically, the red and green LED&#39;s are set to ON. If the lamp is not ON, the backlight  26  is set to OFF. Accordingly, wasteful power consumption during the daytime, when the display unit  24  can be seen relatively easily, is avoided. When these operations have been completed, the controller  23  proceeds to step S 28 , other operations of the display routine such as speed display are executed, and the controller  23  returns to the main routine.  
         [0033]    If the current time does not fall within the period from 6 a.m. to 4 p.m., then the controller  23  advances from step S 21  to step S 25 . In step S 25 , it is determined whether or not the current time is between 4 p.m. and 10 p.m. If the current time falls within this range, then the controller  23  advances to step S 26  and the backlight  26  is set to orange regardless of the ON/OFF state of lamp  50 .  
         [0034]    If the current time does not fall within the period from 4 p.m. to 10 p.m., then the controller  23  advances from step S 25  to step S 27 . In step S 27 , the backlight  26  is set to blue regardless of the ON/OFF state of the lamp. The illumination color is thus changed at night, whereupon the controller  23  proceeds to step  28 . In this routine, the visibility of the information can be increased by changing the color of the backlight  26 , and wasteful power consumption can be avoided.  
         [0035]    If it is determined in step S 3  that key input has been made, then the controller  23  advances to step S 7  and the key input routine is executed. In the key input routine, by repeatedly pressing the left-hand mode button  20   b , the rider can instruct the primary numerical display  52  to display in sequence the distance traveled, the shift position number (i.e., the gear number), the maximum speed, the average speed, and other information.  
         [0036]    When the left-hand mode button  20   b  and the right-hand mode button  20   a  are pressed simultaneously, the contents display  54  displays ‘INT’, and the default value input mode is entered. In the default value input mode, the distance and speed units can be alternated between ‘Km’ and ‘Mile’, and settings for the tire outer circumferential length, the time, the numbers of gears for the front and rear gear shift mechanisms and the like can be input by repeatedly pressing the left-hand mode button  20   b  and sequentially switching among various default values. The first selection is between ‘Km’ and ‘Mile’, and because the default units of ‘Km/h’ and ‘Km’ are flashing, the units to be used are set by causing them to flash using the right-hand mode button  20   a  and entering them by pressing the left-hand mode button  20   b . The rider then moves onto the next setting procedure.  
         [0037]    Tire outer circumferential length setting is then performed, but the setting procedure will not be explained in detail here. When tire outer circumferential length setting is completed, the time is set. The time is displayed on the secondary numerical display  53 , and is set by switching the value to be set to seconds, minutes and finally hours using the left-hand mode button  20   b  and entering the desired value with the right-hand mode button  20   a . When the left-hand mode button  20   a  is pressed after all setting is completed, time setting is ended, and setting of the numbers of gears for the front and rear external gear shift mechanisms  8  and  9  is then performed.  
         [0038]    During setting of the numbers of gears for the front and rear external gear shift mechanisms  8  and  9 , first, because the entire number of rear gears display  55  is flashing, the right-hand mode button  20   a  is pressed several times to cause the number of oval symbols that matches the number of gears on the bicycle to be illuminated. When setting is completed, the left-hand mode button  20   b  is pressed and setting of the number of gears for the number of front gears display  56  is performed. The setting method is the same as that used for the number of rear gears display  55 . The set numbers of gears are stored in the memory  22 , and the data regarding the numbers of gears is maintained until the default values are set once more.  
         [0039]    When all initial settings have been entered, the right-hand mode button  20   a  and the left-hand mode button  20   b  are pressed simultaneously once more and the display apparatus  15  enters normal mode. If the right-hand mode button  20   a  and the left-hand mode button  20   b  are pressed simultaneously for three seconds or longer, the liquid crystal display  25  is initialized, and the CPU  21  can be reset as well.  
         [0040]    By pressing the right-hand mode button  20   b  for three seconds or longer, the gear shift mode can be switched between automatic mode and manual mode. When manual mode is selected, ‘MT’ is displayed in the contents display  54 , while ‘AT’ is displayed if automatic mode is selected.  
         [0041]    With regard to the external gear shift mechanisms  8  and  9 , the relative sizes of the oval symbols in the graphic display in the number of rear gears display  55  and number of front gears display  56  may be arranged so as to correspond to the effective diameters of the gears, as described above, but where the bicycle is using internal gear shift mechanisms, the relative sizes of the oval symbols of the graphic display in the number of rear gears display  55  and the number of front gears display  56  may be arranged so as to correspond to the speed ratios (the speed increase ratio or speed decrease ratio) of the internal gears. Thus, the effect that is achieved with an external gear shift mechanism will be achieved in the case of an internal gear shift mechanism as well.  
         [0042]    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, in the above embodiment, LED&#39;s were used as the light source for the backlight, but other electroluminescent elements may be used as well.  
         [0043]    In the above embodiment, a liquid crystal display screen  25  was used for the display unit  24 , but a light-emitting surface composed of LED&#39;s or other electroluminescent elements may be used as shown in FIG. 8. For example, where red, blue and green LED&#39;s  60   r ,  60   b  and  60   g  are used, the drive circuit  70  that drives the LED&#39;s  60   r ,  60   b  and  60   g  has switching elements Q 1 -Q 3  for each color, which turn ON and OFF based on signals from the controller  23 , ground resistors R 1 -R 3  to reliably extinguish the LED&#39;s  60   r ,  60   b  and  60   g , and current regulating resistors R 4 -R 6  that are disposed between the switching elements Q 1 -Q 3  and the LED&#39;s  60   r ,  60   b  and  60   g . In this case, as shown in FIG. 9, by controlling the period during which the LED&#39;s  60   r ,  60   b  and  60   g  are ON, the hue, color saturation and brightness can be adjusted, enabling a full-color display to be achieved. An example of this type of display is shown in FIG. 10. In FIG. 10, the number of rear gears display  155  and the number of front gears display  156  are displayed in bar chart format. A full-color display can also be achieved if organic electroluminescent elements are used.  
         [0044]    In the above embodiment, the segment method was used for the liquid crystal display screen, but the dot matrix or bit-mapped method may be used instead. In such a case, the various types of information become even easier to see.  
         [0045]    In the description of the flowchart shown in FIG. 7, the color characteristics of the display from the display unit  24  were changed in accordance with the time, which constitutes a temporal state of the bicycling environment, but of course the present invention is not limited to this implementation. Information about the state of the bicycle may be used as well. Such information may include, but is not limited to, bicycle speed, the crank rotation rate (cadence), the remaining capacity in the battery comprising the power supply for the display apparatus, the ON/OFF state of the bicycle&#39;s front lamp, the amount of light emitted from the lamp, the amount of charge remaining where the power supply is charged by a generator, the average speed, the total distance traveled or the like. Information about the physical state of the bicycling environment also may be used. Such information may include, but is not limited to, the slope of the road, the ambient illuminance, atmospheric conditions (temperature, pressure, humidity), the position of the bicycle (longitude and latitude), the distance to an obstacle located in front of the rider, or the like. The characteristic of the bicycling environment also may include a status of the rider such as the rider&#39;s heart rate, blood pressure, calorie consumption, pedaling force, or the like. The inventive features include, but are not limited to, manipulation of the color characteristics of all combinations of the information generated by such data. This includes the features wherein the three color elements of the backlighting display are changed or the three color elements of the light-emitting elements of the display are changed in accordance with various types of information.  
         [0046]    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. 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 on a particular structure or feature.