Abstract:
A vision enhancement device for use in a vehicle that improves the frontward vision of an operator during operation. The device has two dividing lines set apart from each other on an instrument panel. These dividing lines show as false image lines on an inside surface of a front window, and divide the inside surface of the front window into a plurality of areas in a vertical direction. A second area formed between these two false image lines forms an appropriate visual field range when the operator looks forward while operating the vehicle. First light emitting means comprising light emitting diodes are disposed at both ends of each of the two dividing lines. The light emitted by these light emitting diodes is directed onto the front window as a false image in accordance with changes in the vehicle state and the environment around the vehicle.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a vision enhancement device which can be used in a vehicle, which can improve vision in a predetermined area of the windshield (front window), and which can quickly improve the recognition of operating conditions and the like. 
       BACKGROUND OF THE INVENTION 
       [0002]    In recent years, there have been attempts to improve visual recognition of various types of vehicle information without disrupting the attitude (line of sight) of the operator in vision enhancing devices for use in a vehicle. 
         [0003]    In vision enhancing devices of this type for use in a vehicle, priority is given to ensuring a sufficient visual field from the windshield, and a head-up display for use in a vehicle, which reflects operating information and the like on the windshield, is used in order to allow quick recognition of the state of the vehicle during operation. 
         [0004]    Such a head-up display is disclosed in Japanese Patent Application Laid-Open Publication No. 8-227498 (JP 08-227498 A). This head-up display is latterly installed in vehicles that do not have a predetermined installation location. 
         [0005]    The abovementioned head-up display will be described below with reference to  FIG. 13  hereof. 
         [0006]    The conventional head-up display  200  comprises a fluorescent display tube  201  for generating light information, a first reflective plate  202  for reflecting the light information generated by this fluorescent display tube  201 ; a second reflective plate  203  for reflecting the light information reflected by this first reflective plate  202 , and emitting this light information toward the vehicle operator; a driving part  204  for driving the first reflective plate  202 ; a control part  205  for controlling this driving part  204 , and lighting the fluorescent display tube  201 ; and a case  206  for accommodating the fluorescent display tube  201 , first reflective plate  202 , driving part  204 , and control part  205 , and for supporting the second reflective plate  203  in a manner that allows variation. 
         [0007]    However, in a vehicle head-up display  200  of such description, the line of sight must be temporarily directed toward the display in order to confirm the content displayed by the display. 
         [0008]    Furthermore, in the abovementioned head-up display  200 , the content of the display is diverse, which can create a sense of confusion. 
       SUMMARY OF THE INVENTION 
       [0009]    It is an object of the present invention to provide a vision enhancement device for use in a vehicle which can improve the visual recognition of operation while maintaining the line of sight of the operator in a position that is appropriate for operation, and which can inform the operator of the state of the vehicle in a simple manner. 
         [0010]    According to an aspect of the present invention, there is provided a vision enhancement device for use in a vehicle, which comprises: dividing means for making a projection substantially horizontally on a surface of a windshield of the vehicle and thereby dividing the windshield into a plurality of areas, the dividing means being formed such that when the projection is made onto the windshield so as to correspond to a position of a road surface that is a predetermined distance ahead with a vantage point position of an operator used as a starting point, a projection width on the windshield is the same as or smaller than a lane width of the road, wherein the dividing means comprise false image generating means disposed beneath the windshield for showing a false image on the windshield, and first light emitting means for emitting light for at least a portion of the dividing means, the false image generating means being configured so as to form a rectilinear false image that can be recognized in a substantially rectilinear manner from the vantage point position of the operator, the first light emitting means being designed to emit light more brightly in one portion of the rectilinear false image than in another portion. 
         [0011]    When a projection is made for the road surface a predetermined distance ahead with the vantage point position of the operator as a starting point, the dividing means makes a projection onto the windshield so that the projection width is the same as or smaller than the lane width area. Consequently, the operator unconsciously tends to move the vehicle toward the center of the lane, and can be prompted to perform stable driving. 
         [0012]    The first light emitting means is caused to emit light in accordance with changes in the vehicle state and environment surrounding the vehicle, and caused to show this light on the windshield, whereby the operator can be informed that there have been changes in the vehicle state or environment surrounding the vehicle. Specifically, the dividing means is a false image generating means which is disposed beneath the windshield, and forms a substantially rectilinear false image that can be recognized in a substantially rectilinear manner from the vantage point position of the operator. The dividing means comprises first light emitting means is caused to emit light more brightly in one portion of the substantially rectilinear false image than in another portion. Accordingly, the operator can be quickly informed of diverse types of vehicle information without their visual field of the operator being altered. 
         [0013]    Preferably, the false image generating means comprises dividing lines formed on an instrument panel disposed beneath the windshield. Accordingly, the dividing lines formed on the instrument panel will be reflected in the windshield, which can be divided into a plurality of regions. As a result, the false image generating means can be readily constructed. 
         [0014]    Desirably, the false image generating means comprises second light emitting means for forming a substantially rectilinear false image that can be recognized in a substantially rectilinear manner from the vantage point position of the operator. This second light emitting means can also transmit diverse types of vehicle information without the visual field of the operator being altered. 
         [0015]    In a preferred form, the second light emitting means emits light of a color that differs from that of the first light emitting means. Accordingly, the types of information transmission can be increased. 
         [0016]    The first and second light emitting means may be constructed such that at least a portion of these means are capable of flashing. As a result of this flashing, the types of information transmission can be further increased. 
         [0017]    According to a second aspect of the present invention, there is provided a vision enhancement device for use in a vehicle, which comprises: dividing means for making a projection substantially horizontally on a surface of a windshield of a vehicle and thereby dividing the windshield into a plurality of areas, the dividing means being formed so that when the projection is made onto the windshield so as to correspond to a position of a road surface that is a predetermined distance ahead with a vantage point position of an operator used as a starting point, a projection width on the windshield is the same as or smaller than a lane width of the road, wherein the dividing means is disposed beneath the windshield for showing a false image on the windshield, the false image being substantially rectilinear as seen from the vantage point position of the operator, the entirety of the substantially rectilinear false image having a plurality of colors. 
         [0018]    Thus, by varying the light emitted by the dividing means in accordance with variations in the vehicle state and environment surrounding the vehicle, the operator can recognize that there have been variations in the vehicle state or environment surrounding the vehicle. For example, an emergency can be expressed by the color of the emitted light. 
         [0019]    Preferably, at least one portion of the dividing means flashes. In addition to the changing of the emitted light color, an operation whereby the emitted light color itself flashes can be performed. In this way, when there is an emergency variation in the vehicle state or environment surrounding the vehicle, this emergency can be expressed in greater detail. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    Certain preferred embodiments of the present invention will be described in detail below, by way of example only, with reference to the accompanying drawings, in which: 
           [0021]      FIG. 1  is a perspective view of a vision enhancement device for use in a vehicle, according to a first embodiment of the present invention, as seen from the inside of the passenger compartment; 
           [0022]      FIG. 2  is a plan view of the vision enhancement device shown in  FIG. 1 ; 
           [0023]      FIG. 3  is a sectional view taken along line  3 - 3  of  FIG. 2 ; 
           [0024]      FIG. 4  is a schematic view illustrating determination of the length of the dividing means shown in  FIG. 2 ; 
           [0025]      FIG. 5  is a plan view on the road of the vehicle shown in  FIG. 1 ; 
           [0026]      FIG. 6  is a side view of a vehicle mounting the vision enhancement device shown in  FIG. 1 ; 
           [0027]      FIG. 7  is a block diagram showing one example of the control part shown in  FIGS. 1 and 2 ; 
           [0028]      FIG. 8  is a plan view of a vision enhancement device for use in a vehicle, according to a second embodiment of the present invention; 
           [0029]      FIG. 9  is a plan view of a vision enhancement device for use in a vehicle, according to a third embodiment of the present invention; 
           [0030]      FIGS. 10A and 10B  are schematic views illustrating the color variation of the vision enhancement device of the third embodiment shown in  FIG. 9 ; 
           [0031]      FIGS. 11A and 11B  are schematic views showing the variation of the lighting of the vision enhancement device of the third embodiment shown in  FIG. 9 ; 
           [0032]      FIG. 12  is a perspective view of a vision enhancement device for use in a vehicle, according to a fourth embodiment of the present invention, as seen from the inside of the passenger compartment; and 
           [0033]      FIG. 13  is a perspective view of a conventional head-up display for use in a vehicle. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    Reference is now made to  FIGS. 1 through 7  showing a vision enhancement device for use in a vehicle according to a first embodiment of the present invention. 
         [0035]    A vehicle  10  shown in  FIGS. 1 and 2  comprises a steering wheel  14  for steering a vehicle body  11 ; a hood  15  for covering a front part of the vehicle body  11 ; a windshield (front window)  16  for covering a front part of a passenger compartment  12  in a transparent manner; a roof  17  (see  FIG. 6 ) for covering an upper part of the passenger compartment  12 ; an instrument panel  21  disposed in a front part of the passenger compartment  12 ; doors  23  for covering side surfaces of the passenger compartment  12 ; a vehicle seat  24  in which the operator (occupant)  18  (see  FIG. 6 ) is seated; and a vision enhancement device  30  for use in a vehicle to enhance vision so that the line of sight of the operator  18  is maintained in an appropriate position during operation. 
         [0036]    The vision enhancement device  30  for use in a vehicle comprises dividing means  34  for dividing the windshield  16  substantially horizontally into a plurality of areas; i.e., a first area  31 , second area  32 , and third area  33 , and a control part  40  for controlling the first light emitting means  41  of the dividing means  34 . 
         [0037]    The dividing means  34  constitutes false image generating means which is disposed beneath the windshield  16 , and which shows upper and lower false image lines  36  and  37  on the windshield  16 . 
         [0038]    The false image generating means  34  comprises first and second dividing lines  38  and  39  which extend in the vehicle width direction of the instrument panel  21 , and first light emitting means  41  disposed on both end parts of the first and second dividing lines  38  and  39 . 
         [0039]    The first dividing line  38  shows the upper false image line  36  on the windshield  16 . The second dividing line  39  shows the lower false image line  37  on the windshield  16 . 
         [0040]    The first and second dividing lines  38  and  39  have a color that presents a strong contrast to the instrument panel  21 . For example, if the color of the surface of the instrument panel  21  is black, the first and second dividing lines  38  and  39  are formed with a white color or as lustrous chrome plated or other such surface. 
         [0041]    The first and second dividing lines  38  and  39  are formed so that the false image shown on the windshield  16  by the reflection or emission of light from these dividing lines  38  and  39  can be seen in a substantially rectilinear form from the vantage point position of the operator. For example, in cases where the windshield  16  is curved on the side of the passenger compartment  12 , the first and second dividing lines  38  and  39  are formed in a curvilinear shape along this curvature. 
         [0042]    Consequently, the dividing lines  38  and  39  formed on the instrument panel  21  are shown in substantially rectilinear form as false images on the windshield  16 , and divide the surface of the windshield  16  into a plurality of areas. Thus, false image generating means  34  disposed on the instrument panel  21  can be readily constructed. 
         [0043]    The first light emitting means  41  comprise first left and right light emitting assemblies  43  and  44  disposed on either end of the first dividing line  38 , and second left and right light emitting assemblies  45  and  46  disposed on either end of the second dividing line  39 . 
         [0044]    As is shown in  FIG. 3 , the first left light emitting assembly  43  comprises a light emitting diode  51  which acts as a light source, a holder  52  for surrounding the light emitting diode  51 , a substrate  53  for supporting the light emitting diode  51  and holder  52 , and a lens  54  which is attached to the instrument panel  21 , and which transmits the light emitted from the light emitting diode  51 . 
         [0045]    The structures of the first right light emitting assembly  44  and the second left and right light emitting assemblies  45  and  46  are the same as the structure of the first left light emitting assembly  43 . 
         [0046]    As is shown in  FIGS. 4 and 5 , the upper false image line  36  is a line for dividing the windshield  16  into a first area  31  and a second area  32 . The lower false image line  37  is a line for dividing the windshield  16  into a second area  32  and a third area  33 . 
         [0047]    When the dividing lines  38  and  39  are projected onto the windshield  16  in correspondence with the road surface R 2  a predetermined distance H 1  ahead with the vantage point position (eye point)  19  of the operator  18  as a starting point, the length of the lower false image line  37  is formed as a length L 1  which is such that the width H 2  of the road surface R 2  that is the predetermined distance H 1  ahead is the same as or smaller than the lane width H 3  area of the road R 1 . 
         [0048]    For example, if the system is devised so that the visual field of the operator from the windshield is ensured, the line of sight of the operator is maintained in an appropriate position, and the degree of attention to a predetermined area is increased, the operator can be prompted to perform stable driving. Specifically, since the operator  18  is unconsciously caused to move the vehicle  10  toward the center of the lane, the operator  18  can be prompted to perform stable driving. 
         [0049]    As is shown in  FIG. 4 , the windshield  16  is divided into three areas; i.e., a first area  31  formed between the roof  17  and the upper false image line  36 , a second area  32  formed between the upper false image line  36  and the lower false image line  37 , and a third area  33  formed between the lower false image line  37  and the instrument panel  21 . 
         [0050]    When an obstacle is present in a person&#39;s visual field so that this obstacle interferes with the visual field, this obstacle is avoided and the vantage point is moved so that the visual field is maintained. Specifically, the vantage point is determined so that the obstacle is positioned as far as possible in the periphery of the visual field, or so that the obstacle is removed from the visual field. 
         [0051]    In the windshield  16 , the peripheral roof  17  and instrument panel  21  correspond to strong obstacles. The upper and lower false image lines  36  and  37  correspond to weak obstacles. Accordingly, the line of sight of the operator tends to move to the second area  32 , and does not reside for long in the first or third areas  31  or  33  where strong obstacles are present. Furthermore, the line of sight drawn into the second area  32  tends to be directed toward a portion removed from the upper and lower false image lines  36  and  37 , which are weak obstacles. Accordingly, the line of sight is naturally directed toward the vicinity of the center of the second area  32 , and maintained in an appropriate position. 
         [0052]    Thus, as is shown in  FIG. 6 , since the line of sight is directed toward the vicinity of the center of the second area  32 , and is maintained in an appropriate position, a stable visual field is obtained. 
         [0053]      FIG. 7  is a block diagram showing one example of the control part  40  of the vision enhancement device shown in  FIGS. 1 and 2 . 
         [0054]    The control part  40  comprises vehicle state judgment means  74  for judging the state of the vehicle on the basis of information from an ECU  61  which controls the engine and the like, information from various types of sensors  62  through  69 , and information from a radar  71  or information from a camera  72 , and a brightness controller  75  for controlling the first light emitting means  41  from the judgment results of the vehicle state judgment means  74 . 
         [0055]    The brightness controller  75  may be devised so that at least a portion of the first light emitting means  41  flashes, so that the color of the light that is emitted varies, or so that the color of the emitted light itself flashes. Thus, by varying the emitted light, in cases where there are variations in the various types of vehicle conditions or environment surrounding the vehicle, these variations can be expressed to some extent. 
         [0056]    For example, in cases where the vehicle state judgment means  74  judges that the air pressure of the tires is insufficient on the basis of information from an air pressure sensor  62 , the first light emitting means  41  are illuminated or caused to flash by the brightness controller  75 , and the operator is informed that a change in the vehicle state has occurred. In this case, since the lighting or the like of the first light emitting means  41  is shown at both ends of the upper false image line  36  and lower false image line  37  shown on the windshield  16 , the operator can be informed of the change in the vehicle state without their line of sight being altered. 
         [0057]    Furthermore, in cases where the proximity of vehicles ahead, proximity of vehicles behind, or the like is detected by the radar  71 , or the proximity of a pedestrian is detected by the camera  72 , the first light emitting means  41  are illuminated or caused to flash by the brightness controller  75 , and the operator is informed that there has been a change in the environment surrounding the vehicle. 
         [0058]    According to the various types of sensors  63  through  69 , for example, the remaining-fuel sensor  63  detects how much fuel is left, the light bulb burn-out sensor  64  detects that a light bulb has burned out, the remaining-brake-pad sensor  65  detects how much of the brake pads is left, the remaining-washer-liquid sensor  66  detects how much washer liquid is left, the seatbelt sensor  67  detects the fastened or non-fastened state of the seatbelts, the vehicle speed sensor  68  detects the vehicle speed, and the steering angle sensor  69  detects the steering angle. In cases where there is a need for a display on the basis of the various types of information detected by these sensors, the first light emitting means  41  are illuminated or caused to flash by the brightness controller  75 , and the operator is informed that there has been a change in the vehicle state. 
         [0059]    In addition, although this is not shown in the drawings, in cases where the vehicle is detected to have left the lane based on information provided by an HIDS (intelligent driver support system), where communication means informs the operator of the proximity of a vehicle, and where there is a call to a portable telephone or the like, the light emitting means may be illuminated or caused to flash. 
         [0060]      FIG. 8  shows a second embodiment of the vision enhancement device. 
         [0061]    The vision enhancement device  80  shown in  FIG. 8  comprises dividing means  84  for dividing the windshield  16  substantially horizontally into a plurality of areas; i.e., a first area  81 , a second area  82 , and a third area  83 , and a control part  90  for controlling the first light emitting means  91  and second light emitting means  92 . 
         [0062]    The dividing means  84  constitutes false image generating means, which is disposed beneath the windshield  16 , and which shows an upper false image line  86  and a lower false image line  87  on the surface of the windshield  16 . 
         [0063]    The false image generating means  84  preferably comprises first and second dividing lines  88  and  89  disposed on an instrument panel  85 , first light emitting means  91  comprising four light emitting bodies  93 ,  94 ,  95 , and  96  disposed on either end parts of the first and second dividing lines  88  and  89 , and second light emitting means  92  disposed on intermediate parts of the first and second dividing lines  88  and  89 , and comprising a plurality of light emitting bodies  97  and a plurality of light emitting bodies  98  lined up intermittently. 
         [0064]    In cases where there has been a change in the vehicle state, the first and second light emitting means  91  and  92  are illuminated or caused to flash by the control part  90 , and the operator is informed that there has been some kind of change in the vehicle state. In other words, since this lighting or flashing is shown as a false image on the windshield  16 , information is transmitted without altering the visual field of the operator  18  ( FIG. 6 ). 
         [0065]    The second light emitting means  92  can emit light of a different color than that of the first light emitting means  91 . Accordingly, the number of types of vehicle state information can be increased. 
         [0066]    The number of types of vehicle state information can be increased by making it possible for at least portions of the first and second light emitting means  91  and  92  to flash. 
         [0067]      FIG. 9  shows a third embodiment of the vision enhancement device  100 . 
         [0068]    The vision enhancement device  100  of the third embodiment comprises dividing means  104  for dividing the windshield  16  substantially horizontally into a plurality of areas (first through third areas)  101  through  103  and a control part  110  for controlling the first and second light emitting means  111  and  112  of the dividing means  104 . 
         [0069]    The dividing means  104 , which is disposed below the windshield  16 , constitutes false image generating means for showing an upper false line  106  and lower false line  107  on the windshield  16 . 
         [0070]    The false image generating means  104  preferably comprises first light emitting means  111  comprising a light emitting unit  113  consisting of numerous light emitting bodies (light emitting diodes) densely lined up in the form of a line on a substrate disposed on an instrument panel  105 , and second light emitting means  112  comprising a light emitting unit  114  similarly comprising numerous light emitting bodies (light emitting diodes) densely lined up in the form of a line on a substrate disposed on the instrument panel  105 . 
         [0071]    The first light emitting means  111  constitutes a group of light emitting bodies of variable color, and shows an upper false image line  106  on the windshield  16 . The second light emitting means  112  constitutes a group of light emitting bodies of variable color, and shows a lower false image line  107  on the windshield  16 . 
         [0072]    Specifically, the false image generating means  104  is disposed beneath the windshield  16 , and generates a false image which is such that the false image lines can be recognized in substantially rectilinear form from the vantage point position of the operator  18  ( FIG. 6 ). This false image generating means  104  emits light so that the false image lines overall have a plurality of different colors. 
         [0073]      FIGS. 10A and 10B  show an example of the color variation of the vision enhancement device of the third embodiment shown in  FIG. 9 . 
         [0074]    In  FIG. 10A , in the normal state of the vehicle, for example, the first and second light emitting means  111  and  112  emit light with a green color, and the upper and lower false image lines  106  and  107  are shown with a green color on the windshield  16 . 
         [0075]    In  FIG. 10B , in cases where there has been some change in the vehicle state, the upper and lower false image lines  106  and  107  are shown with an orange color or red color on the windshield  16 . 
         [0076]    In this way, by varying the color of the light emitted by the dividing means  14  in accordance with the vehicle state or environment surrounding the vehicle, it is possible to inform the operator that there have been changes in the vehicle state or environment surrounding the vehicle. For example, an emergency can also be expressed by the color of the emitted light. 
         [0077]      FIGS. 11A and 11B  show variation in the lighting of the vision enhancement device of the third embodiment shown in  FIG. 9 . 
         [0078]    In  FIG. 11A , when the steering wheel  14  is turned to the left, the first and second light emitting means  111  and  112  shown in  FIG. 9  are successively illuminated from right to left, and movement is shown in the upper and lower false image lines  106  and  107 , indicating that the vehicle is turning left. 
         [0079]    In  FIG. 11B , when the steering wheel  14  is turned to the right, the first and second light emitting means  111  and  112  are successively illuminated from the left to right, and movement is shown in the upper and lower false image lines  106  and  107 , indicating that the vehicle is turning right. Accordingly, the operator can be informed of changes in the vehicle state. 
         [0080]    The vision enhancement device  100  can cause portions of the first and second light emitting means  111  and  112  shown in  FIG. 9  to flash. If it is thus made possible to cause at least a portion of the false image generating means  104  to flash, a flashing operation of the color of the emitted light itself can be added to the variation in the color of the emitted light, and in cases where there are changes in the vehicle state or environment surrounding the vehicle, emergencies can be expressed in even greater detail. 
         [0081]      FIG. 12  shows a fourth embodiment of the vision enhancement device. 
         [0082]    The vision enhancement device  120  of the fourth embodiment comprises a dashboard tray  122 , which is disposed in the instrument panel  125 , and which can accommodate small objects, lamps (or light emitting bodies)  126 ,  126  which illuminate the interior of the dashboard tray  122 , and a control part  130  for controlling these lamps  126 ,  126 . A dividing line  123  disposed on the dashboard tray  122  is projected onto the windshield  16 , and the system is devised so that the light of the lamps  126 ,  126  leaks out from the corners of the dashboard tray  122 . 
         [0083]    The dividing line  123  is formed by the front and rear edges  136 ,  137  and left and right edges  138 ,  139  of the dashboard tray  122 . The external shape of the dashboard tray  122  is defined so that when the dividing line  123  is projected onto the windshield  16 , the front and rear edges  136 ,  137  and left and right edges  138 ,  139  are projected in a substantially rectilinear form. 
         [0084]    In cases where there is a change in the vehicle state, the lamps  126 ,  126  are illuminated or caused to flash by the control part  130 , and the operator is informed that there has been some change in the vehicle state. 
         [0085]    For example, in cases where a portable telephone is accommodated inside the dashboard tray  122 , the vibration or incoming calls of the portable telephone are detected, and the lamps  126 ,  126  are illuminated or caused to flash. 
         [0086]    In the vision enhancement device  30  for use in a vehicle according to the first embodiment, an example was described in which the light emitting bodies  43  through  46  of the first light emitting means  41  were simultaneously illuminated or simultaneously caused to flash. However, the present invention is not limited to such an arrangement; it would also be possible for the light emitting bodies  43  through  46  to be separately illuminated or made to flash. 
         [0087]    The vision enhancement device of the present invention for use in a vehicle described above is suitable for use in passenger vehicles such as sedans, wagons, or the like. 
         [0088]    Obviously, various minor changes and modifications of the present invention are possible in light of the above teaching. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.