Abstract:
Provided is a vehicular heads-up display device with which it is possible to avoid burn-in of an internal component upon a reflecting member by exterior light, improving display quality. A vehicular heads-up display device, comprising a case body ( 50 ) whereon an aperture part ( 51   c ) is disposed and a light-emitting body ( 30 ) that is housed within the case body ( 50 ) reflects emitted light L that is emitted by the light-emitting body ( 30 ) externally to the case body ( 50 ) via the aperture part ( 51   c ) and reflects said emitted light L from the windshield ( 13 ), causing the driver ( 14 ) to have sight of the virtual image V that is obtained by said reflection. The vehicular heads-up display device further comprises a semi-transmissible cover ( 55 ) installed in the aperture part ( 51   c ), and a dispersal means ( 58 ) is disposed between the light emitting body ( 30 ) and the cover ( 55 ), for dispersing exterior light that enters the case body ( 50 ) via the cover ( 55 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a vehicular heads-up display device configured to cause outgoing light emitted from a light-emitting body to reflect on a windshield, which is a reflecting member, of a vehicle and cause a virtual image obtained by the reflection to be visually identified by a user of the vehicle. 
       BACKGROUND ART 
       [0002]    In the related art, as a vehicular heads-up display device of this type, for example, the one disclosed in Patent Literature 1 shown below is known. The vehicular heads-up display device described in Patent Literature 1 is mounted inside an instrument panel (hereinafter, referred to as “INP”) of the vehicle, and includes a liquid crystal display configured to issue travelling information relating to travel of the vehicle as display light, a light source (a light-emitting body) composed of an LED disposed adjacent to the liquid crystal display, a circuit board on which a wiring pattern for mounting the light source is formed, a reflection mirror configured to reflect the display light emitted by the liquid crystal display and outgoing light (illumination light) emitted from the light source, and a unit case (case body) configured to house the liquid crystal display, the light source, the circuit board, and the reflection mirror, and an opening to allow the display light and the outgoing light described above reflected by the reflection mirror to pass therethrough is formed on the upper end side of the unit case so as to open. 
         [0003]    Then, the vehicular heads-up display device configured as described above is configured to cause the display light from the liquid crystal display reflected by the reflection mirror and the outgoing light from the light source to go out to the outside of the unit case via the opening provided in the unit case, and to reflect on a windshield of the vehicle as a reflecting member toward a driver, and allows a user of the vehicle as a driver to visually identify a virtual image obtained by this reflection. 
         [0004]    In this case, the vehicular heads-up display device includes control means including a microcomputer configured to cause the liquid crystal display to perform a display operation and cause the light source to perform a lighting operation mounted on the circuit board, and such control means causes the liquid crystal display to perform the display operation to display also a signage “CHECK” in addition to the traveling information (vehicle speed display) on the liquid crystal display and, simultaneously, causes the light source to perform the lighting operation to display a circular alarm sign, described later, as part of the virtual image upon reception of a state signal indicating that only a small amount of fuel remains for example. 
         [0005]    Then, the light source is illuminated simultaneous with the emission of vehicle speed display light and signage display light such as “CHECK” from the liquid crystal display, and the vehicle sped display light, the signage display light, and the outgoing light emitted from the light source are reflected toward the driver through a reflection mirror, the opening of the unit case, and the windshield, whereby the driver is capable of observing the virtual image composed of the vehicle speed display, the signage display such as “CHECK”, and the circular alarm sign with a landscape superimposed thereon. The alarm sign displayed as part of the virtual image is displayed for letting the driver to reliably notify the fact that the signage display such as “CHECK” is displayed. 
       CITATION LIST 
     Patent Literature 
       [0000]    
       
         PTL: JP-A-4-184481 
       
     
       SUMMARY OF INVENTION 
     Solution to Problem 
       [0007]    However, in the case of the vehicular heads-up display device in Patent Literature 1 described above, there is a problem that sun light (outside light) incident on and entering the unit case through the opening formed on the upper end side of the unit case illuminates internal components (the circuit board formed with the wiring pattern thereon, the light source, or the like) housed in the unit case and, by the reflected light therefrom, the internal components are reflected as a background on the front glass (reflecting member) as a residual image, which may bother the driver. 
         [0008]    In addition, since the alarm sign described above is displayed only when reminding the driver to pay attention, the rate of awareness by the driver is low unlike the vehicle speed display which is always displayed, and hence misidentification of the image of the internal components reflected as the background due to the influence of the outside light and the image of the alarm sign may occur. 
         [0009]    Accordingly, in order to solve the above-described problem, it is an object of the invention to provide a vehicular heads-up display device which is capable of preventing reflection of internal components as a background on a reflecting member due to outside light, and improving a display quality. 
       Solution to Problem 
       [0010]    The invention provides a vehicular heads-up display device including: a case body formed with an opening; and a light-emitting body housed in the case body, wherein an outgoing light from the light-emitting body is caused to go out toward the outside of the case body through the opening and reflect by a predetermined reflecting member so as to allow a user of a vehicle to visually identify a virtual image obtained by the reflection, including: a semi-permeable cover disposed on the opening; and a diffusing means configured to diffuse outside light incident on and entering the case body through the cover between the light-emitting body and the cover. 
         [0011]    The invention is characterized by including a display portion having a predetermined display design and a background portion forming a background of the display portion on a front surface or a back surface of the cover. 
         [0012]    The invention is also characterized in that the diffusing means is provided on the back side of the cover so as to cover the display portion and the background portion or so as to be interposed between the cover and the background portion. 
         [0013]    The invention is also characterized by including a display member provided with the display portion having a predetermined display design and the background portion forming the background of the display portion on a light-permeable substrate between the light-emitting body and the cover, and in that the diffusing means is provided between the substrate and the cover. 
         [0014]    The invention is also characterized in that the diffusing means is provided between the light-emitting body and the cover so as to be apart from the cover, and the diffusing means is provided with the display portion having a predetermined display design and the background portion forming a background of the display portion. 
         [0015]    The invention is also characterized in that the color tone of the cover includes a dark color. 
       Advantageous Effects of Invention 
       [0016]    According to the invention, an initial object is achieved and a vehicular heads-up display device which is capable of preventing reflection of internal components as a background on a reflecting member due to outside light, and improving display quality is provided. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0017]      FIG. 1  is a schematic drawing illustrating a vehicular heads-up display device according to a first embodiment of the invention. 
           [0018]      FIG. 2  is a cross-sectional view illustrating a light-emitting device according to the same embodiment. 
           [0019]      FIG. 3  is an enlarged cross-sectional view illustrating a portion A in  FIG. 2  in an enlarged scale. 
           [0020]      FIG. 4  is a block diagram illustrating an electric configuration of the vehicular heads-up display device according to the same embodiment. 
           [0021]      FIG. 5  is a front view of a windshield in a state in which a virtual image is displayed according to the same embodiment. 
           [0022]      FIG. 6  is a cross-sectional view of a display member according to a modification of the same embodiment. 
           [0023]      FIG. 7  is a cross-sectional view of a display member according to another modification of the same embodiment. 
           [0024]      FIG. 8  is a cross-sectional view illustrating a light-emitting device according to a second embodiment of the invention. 
           [0025]      FIG. 9  is a cross-sectional view illustrating a light-emitting device according to a third embodiment of the invention. 
           [0026]      FIG. 10  is a cross-sectional view illustrating a light-emitting device according to a fourth embodiment of the invention. 
           [0027]      FIG. 11  is a cross-sectional view illustrating a light-emitting device according to a modification of the same fourth embodiment. 
           [0028]      FIG. 12  is a cross-sectional view illustrating a light-emitting device according to another modification of the same fourth embodiment. 
           [0029]      FIG. 13  is a cross-sectional view illustrating a light-emitting device according to a fifth embodiment of the invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
       [0030]    Referring now to  FIG. 1  to  FIG. 5 , an embodiment in which the invention is applied to a vehicular heads-up display device will be described below. 
         [0031]    The vehicular heads-up display device is configured to cause outgoing light L emitted from a light-emitting device  12  disposed inside an INP  11 , which is a reflecting member, of a vehicle  10  to be reflected by a windshield  13  of the vehicle  10  toward a driver (user)  14  of the vehicle  10  to display a virtual image V as illustrated in  FIG. 1 . In other words, the vehicular heads-up display device is configured to allow the outgoing light L emitted from alight source, described later, of the light-emitting device  12  to go out toward the windshield  13  (the reflecting member), and allow the driver  14  to visually identify the virtual image V obtained by the outgoing light. Accordingly, the driver  14  is allowed to observe the virtual image V displayed in the forward front of a driver&#39;s seat with a landscape superimposed thereon. 
         [0032]    The light-emitting device  12  mainly includes a circuit board  20 , a light source  30  as a light-emitting body mounted (disposed) on the circuit board  20 , a lens member  40  configured to focus the outgoing light emitted from the light source  30 , and a case body  50  which constitutes an outer case of the light-emitting device  12  as illustrated in  FIG. 2  in detail. 
         [0033]    The circuit board  20  is formed of a hard circuit board provided with, for example, a predetermined wiring pattern thereon, and the light source  30  is mounted on the wiring pattern. The circuit board  20  as described above is mounted on a bottom wall portion provided on a lower case, described later, of the case body  50 . 
         [0034]    The light source  30  includes, for example, a chip-type light-emitting diode emitting red light, and is a light-emitting body that supplies illumination light (the outgoing light) to the lens member  40 . 
         [0035]    The lens member  40  is formed of a translucent synthetic resin, and includes a convex lens  41  having a flat surface on the back side (the light source  30  side) and a convex surface on the front side opposite from the back side and a pair of flanges  42  extending in the periphery of the convex lens  41 , and has a function as a light-gathering member configured to gather the outgoing light emitted from the light source  30 . In other words, the lens member  40  (convex lens  41 ) is configured to give a predetermined refraction to the outgoing light so as to let parallel outgoing light which is a substantially parallel pencil go out toward an opening formed so as to open on an upper case, described later, of the case body  50 . 
         [0036]    The case body  50  is formed of, for example, a black light-shielding synthetic resin material, and in this case, is divided into an upper case  51  and a lower case  52 . The upper case  51  and the lower case  52  are both formed to have a substantially concave shape in cross section, and the circuit board  20 , the light source  30 , and the lens member  40  are accommodated in a space portion  53  (in other words, in the interior of the case body  50 ) as an internal space defined by the upper case  51  and the lower case  52 . 
         [0037]    The upper case  51  has a configuration in which a front wall portion  51   a  positioned on the windshield  13  side and a substantially frame-shaped first side wall portion  51   b  formed so as to extend downward (toward the lower case  52 ) from a peripheral edge of the front wall portion  51   a  are formed integrally. Then, an opening  51   c  formed of a substantially rectangular opening window is formed so as to open at a substantially center portion of the front wall portion  51   a  of the upper case  51  (see  FIG. 3 ), and a display member  54  formed of a design panel, which is a separate member from the case body  50 , is disposed on the opening  51   c  so as to close the opening  51   c.    
         [0038]    In this case, the front wall portion  51   a  is provided with a holding portion  51   d  having a brim shape formed so as to project inward from the opening  51   c  (that is, from the inner wall surface of the front wall portion  51   a ) so as to hold a flange portion, described later, of the display member  54  at a lower end side thereof, and the display member  54  (that is, a cover  55  described later as a base material of the display member  54 ) is disposed on the opening  51   c  so as to close the opening  51   c  by the flange portion held by the holding portion  51   d.    
         [0039]    The display member  54  includes a semipermeable cover  55  formed of a translucent synthetic resin plate (or a glass plate) having, for example, a dark smoke color tone, a display portion  56  formed of a predetermined display design (permeable design portion) provided on the front surface of the cover, a background portion  57  formed of a light-shielding layer provided on the front surface of the cover  55  so as to form a background of the display portion  56 , and a diffusing sheet (diffusing means)  58  provided on the back surface of the cover  55  between the light source  30  and the cover  55  in order to cause the sun light (outside light) incident on and entering the space portion  53  (the interior of the case body  50 ) through the display portion  56  and the cover  55  to diffuse (diffusely reflect), and the diffusing sheet  58  is stuck to the cover  55  in tight contact with the back surface of the cover  55  using securing means as needed as illustrated in  FIG. 3 . 
         [0040]    The cover  55  has a dark color tone, and has a configuration including a curved surface portion  55   a  formed into a curved surface shape (curved shape) having a predetermined curvature, and a flange portion  55   b  having a brim shape positioned around the curved surface portion  55   a  so as to surround the curved surface portion  55   a  formed integrally to each other. 
         [0041]    For reference, the curved surface shape of the curved surface portion  55   a  in this case is set to have the curvature which prevents the reflected light therefrom from being directed toward the driver  14  side via the windshield  13 , for example, when sun light (outside light) is impinged on the curved surface portion  55   a  and reflected therefrom. In other words, this means that the curved surface portion  55   a  is formed to have the curved surface shape which prevents the reflected light reflected upon reception of the outside light from being directed toward the driver  14  side. 
         [0042]    The display portion  56  having a permeable design portion is formed of a void portion  59  where the background portion  57  is not formed partway so as to expose part of the cover  55 , and is formed at a substantially center portion of the cover  55 . For reference, in this example, the design shape of the display portion  56  provided at a position of the void portion  59 , which is an area from which the background portion  57  is removed is a circular shape. However, it is needless to say that any shapes other than the circular shape may also be employed as the design shape of the display portion  56 . 
         [0043]    The background portion  57  composed of a light-shielding layer is formed of a printed layer formed on the front surface of the cover  55  by printing and is formed by printing by means of screen printing or the like using black ink, for example. Then, the display portion  56  is formed as the void portion  59  where the printed layer which forms the background portion  57  is not formed by printing a portion corresponding to the display portion  56  by hollow printing when printing the background portion  57 . 
         [0044]    In contrast, the lower case  52  has a configuration including a bottom wall portion  52   a  which is a placing portion for placing the circuit board  20  on which the light source  30  is mounted, and a substantially frame-shaped second side wall portion  52   b  which becomes paired with the first side wall portion  51   b  of the upper case  51  formed integrally with each other, and the second side wall portion  52   b  is provided with a supporting portion  52   c  having a step shape for supporting a peripheral edge of the flanges  42  of the lens member  40  at an upper end portion thereof. 
         [0045]    The respective portions described above constitute the light-emitting device  12 . Subsequently, an electric configuration of the vehicular heads-up display device according to this embodiment will be described with reference to  FIG. 4 . In  FIG. 4 , reference numeral  61  designates vehicle speed detecting means, reference numeral  62  designates control means, reference numeral  63  designates a light source drive circuit, and reference numeral  30  designates the light source. 
         [0046]    The vehicle speed detecting means  61  includes a vehicle speed sensor for detecting the speed of the vehicle, and is configured to detect a vehicle-speed detection signal according to an operating state of the vehicle and output the signal to the control means  62 . 
         [0047]    The control means  62  is composed of a microcomputer including a ROM in which a program of a processing operation is stored, a RAM configured to temporarily store a computed value, and a CPU for executing the program and, in this case, is mounted on a wiring board, not illustrated, fixedly disposed in the light-emitting device  12  (the space portion  53 ). 
         [0048]    The control means  62  as described above outputs a command signal that controls the operation of the light source  30  on the basis of the vehicle speed detection signal from the vehicle speed detecting means  61 . Specifically, lighting control of the light source  30  is performed as described below on the basis of the vehicle speed detection signal. In other words, in the case of this example, the control means  62  outputs a command signal for causing the light source  30  to perform a lighting operation only when the value of the vehicle speed detection signal input according to the operating state of the vehicle exceeds a predetermined threshold value (for example, 100 km per hour). 
         [0049]    The command signal output from the control means  62  is input to the light source drive circuit  63  configured to drive the light source  30 . The light source drive circuit  63  drives the light source  30  upon reception of the command signal, whereby the light source  30  is lit. 
         [0050]    Then, when the light source  30  is lit at a vehicle speed exceeding 100 km per hour, the outgoing light L emitted from the light source  30  passes through the convex lens  41 , and then goes out from the convex lens  41  as the parallel outgoing light. The parallel outgoing light (that is, the outgoing light L from the light source  30 ) as described above goes out to the outside of the case body  50  via the display member  54  disposed in the opening  51   c.    
         [0051]    At this time, the parallel outgoing light (the outgoing light L from the light source  30 ) passes through the diffusing sheet  58 , the curved surface portion  55   a  (the cover  55 ), and the circular display portion  56 , goes out toward the windshield  13  side, and further is reflected by the windshield  13  toward the driver  14  side. The driver  14  is capable of visually identifying a circular red light-emitting image (the virtual image V) corresponding to the design shape of the display portion  56  obtained by the reflection (see  FIG. 5 ). In this manner, according to the invention, the alarm sign indicating an overspeed displayed for the driver  14  using the circular red light-emitting image (the virtual image V) reminds the driver  14  to pay attention. 
         [0052]    For reference, the brightness of the parallel outgoing light (the outgoing light L) is attenuated when passing through the curved surface portion  55   a  (the cover  55 ) having a smoke color tone. However, since the vehicular heads-up display device of the invention is intended to remind the driver to pay attention, if the brightness is attenuated, the display only becomes cloudy, but the display quality is not impaired. Also, in this example, the display portion  56  and the background portion  57  are formed on the front surface of the cover  55 . For example, however, a configuration in which the display portion  56  and the background portion  57  are eliminated, and the parallel outgoing light (the outgoing light L) passing through the cover  55  goes out toward the windshield  13  side without passing through the display portion  56 . 
         [0053]    Subsequently, how the sun light (the outside light) travels in the case body  50  will be described. The outside light incident on and entering the case body  50  is reflected by the curved surface at the portion of the curved surface portion  55   a  corresponding to the void portion  59  toward the windshield  13  side and then is attenuated when part of the light passes further the portion of the curved surface portion  55   a  corresponding to the void portion  59 . Then, part of the outside light passing through the portion of the curved surface portion  55   a  corresponding to the void portion  59  is diffused (diffusely reflect) by the diffusing sheet  58  provided on the back surface of the curved surface portion  55   a  (the cover  55 ), and hence in this configuration, internal components such as the circuit board  20  or the light source  30  housed in the case body  50  are not illuminated. Therefore, the reflection of the internal components as a background on the windshield (the reflecting member)  13  due to the outside light is prevented, the driver  14  is capable of visually identifying the red light-emitting image (the virtual image V) having no remaining image, so that the vehicular heads-up display device improved in display quality may be provided. 
         [0054]    As described above, in this embodiment, in the vehicular heads-up display device including the case body  50  formed with the opening  51   c  and the light source (light-emitting body)  30  housed in the case body  50 , and configured to cause the outgoing light L from the light source  30  to go out to the outside of the case body  50  via the opening  51   c  and be reflected by the windshield  13  and allow the driver  14  as an user of the vehicle to visually identify the virtual image V obtained by this reflection, the semi-permeable cover  55  disposed on the opening  51   c  is provided, and the diffusing sheet  58  as the diffusing means configured to diffuse the outside light incident on and entering the case  50  through the cover  55  is provided between the light source  30  and the cover  55 . 
         [0055]    Therefore, a configuration in which part of the outside light incident on and entering the case body  50  via the cover  55  (or the display portion  56  and the cover  55 ) is diffused (diffusely reflected) by the diffusing sheet  58  and does not positively illuminate the internal components such as the circuit board  20  and the light source  30  housed in the case body  50  is achieved, so that the reflection of the internal components as a background on the windshield  13  by the outside light is prevented, and improvement of the display quality of the virtual image V is enabled. 
         [0056]    Also, in this embodiment, the front surface of the cover is provided with the display portion  56  having a substantially circular display design and the background portion  57  formed of the light-shielding layer forming the background of the display portion  56 , whereby the parallel outgoing light (the outgoing light emitted from the light source  30 ) goes out through the cover  55  and the display portion  56  as a substantially circular permeable design portion to the windshield  13 . Therefore, the outline of the virtual image V (the circular red light-emitting image) reflected on the windshield  13  becomes clear, so that improvement of the display quality of the virtual image V is enabled. 
         [0057]    Also, in this embodiment, the example in which the display portion  56  is formed as the void portion  59  where the background portion  57  is not formed when forming the background portion  57  by printing has been described. However, for example, the display portion  56  may be formed as a printed layer having a predetermined color such as white. 
         [0058]    Also, in this embodiment, the example in which the diffusing means  58  is formed of a diffusing sheet stuck to the back surface of the cover  55  has been described. However, the diffusing means  58  may be realized, for example, by grain finish or the like applied on the back surface of the cover  55  instead of the diffusing sheet. 
         [0059]    Also, in this embodiment, the example in which the background portion  57  is formed on the front surface of the cover  55  (that is, the front surface of the curved surface portion  55   a  and the front surface of the flange portion  55   b ) by printing has been described. However, for example, the background portion  57  may be formed only on the front surface of the curved surface portion  55   a  of the cover  55  by printing. 
         [0060]    Also, in this embodiment, the example in which the background portion  57  is formed on the front surface of the cover  55  and the display portion  56  is formed in the area other than the background portion  57 , and the diffusing sheet  58  is stuck on the back surface of the cover  55  has been described. For example, however, even when the background portion  57  is formed on the back surface of the cover  55  instead of the front surface of the cover  55  and the diffusing sheet  58  is provided on the back side of the cover  55  so as to cover the background portion  57  and the display portion  56  as a modification of this embodiment as illustrated in  FIG. 6 , or even when the diffusing sheet  58  is stuck on the back surface of the cover  55  and the background portion  57  is formed so as to be laminated on the back surface of the diffusing sheet  58  as another modification of this embodiment as illustrated in  FIG. 7 , the same effects and advantages as in this embodiment described above are achieved. In  FIG. 7 , the diffusing sheet  58  is provided on the back side of the cover  55  so as to be interposed between the cover  55  and the background portion  57 , and the display portion  56  (the void portion  59 ) is provided as an exposed portion from which the back side of the diffusing sheet  58  is partly exposed. 
       Second Embodiment 
       [0061]    Subsequently, referring now to  FIG. 8 , a second embodiment of the invention will be described, and the same or corresponding parts are designated by the same reference signs as those of the first embodiment described above, and detailed description thereof will be omitted. The second embodiment is configured in such a manner that the background portion  57  formed on the front surface of the semi-permeable cover  55  having a smoked color tone is eliminated, and a design panel (display member)  70  is arranged between the light source  30  (the lens member  40 ) and the cover  55 . 
         [0062]    In other words, in the second embodiment, the cover  55  (not formed with the background portion  57 ) is disposed on the opening  51   c , and the diffusing sheet  58  as diffusing means configured to diffuse the outside light incident on and entering the case body  50  through the cover  55  is stuck on the back side of the cover  55 , and the design panel  70  is arranged between the light source  30  an the cover  55 . 
         [0063]    The design panel  70  configured in this manner is formed of a translucent (light permeable) substrate  71  as a base material formed of an acrylic resin, and includes a display portion  72  having a predetermined display design on the front surface of the substrate  71 , and a background portion  73  forming a background of the display portion  72 . The display portion  72  has a design shape equivalent to the display portion  56  employed in the first embodiment, and the background portion  73  has the design shape equivalent to the background portion  57  employed in the first embodiment. For reference, in this case, the display member  70  is fixed to the case body  50  (the upper case  51 ) using fixing means as needed. 
         [0064]    In the second embodiment as well as described above, part of the outside light incident on and entering the case body  50  is diffused (diffusely reflected) by the diffusing sheet  58  provided on the back side of the cover  55  between the substrate  71  and the cover  55 , and hence in this configuration, the internal components such as the circuit board  20 , the light source  30 , and the display portion  72  housed in the case body  50  are not illuminated. Therefore, the reflection of the internal components as a background on the front glass (reflecting member)  13  due to the outside light is prevented, the driver  14  is capable of visually identifying the red light-emitting image (the virtual image V) having no remaining image, so that the same effects and advantages as in the first embodiment are obtained. 
         [0065]    Also, in the second embodiment, the example in which the substrate  71  is formed of a light-permeable acrylic resin has been described. However, for example, the substrate  71  may be formed of a semi-permeable synthetic resin plate (or the glass plate) having a smoke color tone. 
         [0066]    Also, in the second embodiment, the example in which the background portion  73  is formed on the front surface of the substrate  71  has been described. However, for example, the background portion  73  may be formed on a back surface of the substrate  71  instead of the front surface of the substrate  71 . At this time, it is needless to say that the display portion  72  is formed at a substantially center portion of the back surface of the substrate  71 . 
         [0067]    In the second embodiment, the example in which the display member  70  arranged between the light source  30  and the cover  55  is formed of the design panel having the display portion  72  and the background portion  73  has been described. However, the design panel may be replaced by a known dot-matrix liquid crystal display panel. In this case, a display portion corresponding to the display portion  72  having a circular design shape may be formed at a substantially center portion of the liquid crystal display panel. 
       Third Embodiment 
       [0068]    Subsequently, referring now to  FIG. 9 , a third embodiment of the present invention will be described, and the same or corresponding parts are designated by the same reference signs as those of the first and second embodiments described above, and detailed description thereof will be omitted. In the third embodiment, with the configuration of the second embodiment as a basic configuration, the background portion  73  provided on the design panel  70  is formed on the back surface of the substrate  71  and the diffusing sheet  58  is provided on the front surface of the substrate  71  instead of the back surface of the cover  55  so as to be in tight contact therewith. 
         [0069]    In the third embodiment as well, part of the outside light incident on and entering the case body  50  is attenuated and reaches the design panel  70  when passing through the cover  55 , and part of the outside light reaching the design panel  70  is diffused (diffusely reflected) by the diffusing sheet  58  provided on the front surface of the substrate  71  between the substrate  71  and the cover  55 , and hence with this configuration, the internal components such as the circuit board  20  and the light source  30  housed in the case body  50  are not illuminated. Therefore, the reflection of the internal components as a background on the windshield (the reflecting member)  13  due to the outside light is prevented, the driver  14  is capable of visually identifying the red light-emitting image (the virtual image V) having no remaining image, so that the same effects and advantages as in the first and second embodiments may be obtained. 
         [0070]    According to the configuration of the third embodiment, the background portion  73  is provided on the back surface of the substrate  71  and the diffusing sheet  58  is stuck on the front surface of the substrate  71 . However, for example, a configuration in which the background portion  73  is provided on the front surface of the substrate  71  and the diffusing sheet  58  as the diffusing means is overlapped on the front side of the substrate  71  so as to cover the background portion  73  and the display portion  72  provided in the area other than the background portion  73  is also applicable. 
       Fourth Embodiment 
       [0071]    Subsequently, referring now to  FIG. 10 , a fourth embodiment of the invention will be described, and the same or corresponding parts are designated by the same reference signs as those of the first to third embodiments described above, and detailed description thereof will be omitted. In the fourth embodiment, with the configuration of the third embodiment as a basic configuration, the design panel  70  and the diffusing sheet  58  are eliminated and, for example, a thin-plate-shaped diffusing member (diffusing means)  80  formed of a light-permeable synthetic resin of a milky white color is provided, and a display portion  81  having a predetermined display design and a background portion  82  forming the background of the display portion  81  are provided on a back surface of the diffusing member  80 . 
         [0072]    In this case, the diffusing member  80  is provided on the rear side of the cover  55  so as to be apart from the cover  55 , has a function to diffuse the outside light incident on and entering the case body  50  through the cover  55 , and is fixed to the case body  50  (the upper case  51 ) using the fixing means as needed. The display portion  81  has a design shape equivalent to the display portion  72  employed in the third embodiment, and the background portion  82  has the design shape equivalent to the background portion  73  employed in the third embodiment. 
         [0073]    In the fourth embodiment as well, part of the outside light incident on and entering the case body  50  is attenuated when passing through the cover  55  and reaches the diffusing member  80 , and part of the outside light reaching the diffusing member  80  is diffused (diffusely reflected) by the diffusing member  80 , and hence with this configuration, the internal components such as the circuit board  20  and the light source  30 , housed in the case body  50  are not illuminated. Therefore, the reflection of the internal components as a background on the windshield (reflecting member)  13  due to the outside light is prevented, the driver  14  is capable of visually identifying the red light-emitting image (the virtual image V) having no remaining image, so that the same effects and advantages as in the first to the third embodiments may be obtained. 
         [0074]    Also, in the fourth embodiment, the example in which the background portion  82  is formed on the back surface of the diffusing member  80  has been described. However, the background portion  82  may be formed only on the surface of the diffusing member  80 . At this time, the display portion  81  is formed on the front surface of the diffusing member  80  as a matter of course. 
         [0075]    As illustrated in  FIG. 11  as a modification of the fourth embodiment, the background portion  82  corresponding to the background portion  57  employed in the first embodiment may be formed on the front surface of the cover  55  instead of forming the background portion  82  on the back surface of the diffusing member  80  provided on the rear side of the cover  55  so as to be apart from the cover  55 . At this time, the display portion  81  corresponding to the display portion  56  employed in the first embodiment is formed in the area other than the background portion  82 . As another modification of the fourth embodiment as illustrated in  FIG. 12 , it is needless to say that the background portion  82  and the display portion  81  may be provided on the back surface of the cover  55  (the curved surface portion  55   a ) instead of the front surface of the cover  55 , and the diffusing member  80  may be provided between the cover  55  and the light source  30  so as to be apart from the cover  55 . 
       Fifth Embodiment 
       [0076]    Subsequently, referring now to  FIG. 12 , a fifth embodiment of the invention will be described, and the same or corresponding parts are designated by the same reference signs as those of the first to the fourth embodiments described above, and detailed description thereof will be omitted. In the fifth embodiment, with the configuration of the second embodiment as a basic configuration, the diffusing sheet  58  stuck on the back surface of the cover  55  is eliminated and, for example, a thin-plate-shaped diffusing member (diffusing means)  90  formed of a light-permeable synthetic resin having a milky white color is arranged on the front side (between the display member  70  and the cover  55 ) of the design panel  70 . 
         [0077]    The diffusing member  90  has a function to diffuse the outside light incident on and entering the case body  50  through the cover  55 , is positioned between the design panel  70  and the cover  55 , and is fixed to the case body  50  (the upper case  51 ) using the fixing means as needed. In the fifth embodiment as well, part of the outside light incident on and entering the case body  50  is attenuated when passing through the cover  55  and reaches the diffusing member  90 , and part of the outside light reaching the diffusing member  90  is diffused (diffusely reflected) by the diffusing member  90 , and hence with this configuration, the internal components such as the circuit board  20 , the light source  30 , and the display member  70  housed in the case body  50  are not illuminated. Therefore, the reflection of the internal components as a background on the windshield (the reflecting member)  13  due to the outside light is prevented, the driver  14  is capable of visually identifying the red light-emitting image (the virtual image V) having no remaining image, so that the same effects and advantages as in the first to the fourth embodiments may be obtained. 
         [0078]    In the respective embodiments described above, the virtual image V as a red light-emitting image is displayed in association with the lighting of the light source  30 . However, the virtual image V as a red light-emitting image may be flashed by flashing the light source  30 , for example. In this manner flashing display of the virtual image V may enhance an effect of inviting the driver  14 &#39;s attention. 
         [0079]    In addition, in the respective embodiment described above, the example in which the virtual image V as a circular red light-emitting image is displayed in association with the lighting of the light source  30  when the vehicle speed exceeds the threshold value to remind the driver  14  to pay attention (raise a red flag) has been described. However, for example, a configuration in which the virtual image V is displayed (flashed) when the remaining amount of fuel is reduced beyond a predetermined value or when a distance between the vehicle in concern and a vehicle traveling in the front is reduced beyond a predetermined distance to remind the driver  14  to pay attention (raise a red flag) is also applicable. 
         [0080]    In the respective embodiments described above, the example in which the lens shape of the convex lens  41  of the lens member  40  is a plano-convex lens shape in which the back side (the light source  30  side) is flat and the front side (the side of the front wall portion  51   a  of the case body  50 ) is a convex surface has been described. However, for example the convex lens  41  having a double-convex lens shape in which the light source  30  side and the front wall portion  51   a  side are both convex surfaces may be applied. 
         [0081]    In the respective embodiments described above, the example in which the outgoing light L emitted from the light source  30  goes out toward the windshield  13  has been described. However, for example, a combiner film which causes the outgoing light L to be reflected desirably toward the driver  14  may be provided on the windshield  13 , or a configuration in which the outgoing light L goes out toward a specific reflecting member different from the windshield  13  is also applicable. 
       INDUSTRIAL APPLICABILITY 
       [0082]    The invention is applicable to a vehicular heads-up display device configured to cause outgoing light emitted from a light-emitting body to reflect on a windshield of a vehicle and cause a virtual image obtained by the reflection to be visually identified by a user of the vehicle. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           12  light-emitting device 
           13  windshield (reflecting member) 
           14  driver (user) 
           20  circuit board 
           30  light source (light-emitting body) 
           40  lens member 
           41  convex lens 
           50  case body 
           51  upper case 
           51   c  opening 
           52  lower case 
           53  space portion 
           54  display member 
           55  cover 
           55   a  curved surface portion 
           55   b  flange portion 
           56 ,  72 ,  81  display portion 
           57 ,  73 ,  82  background portion 
           58  diffusing sheet (diffusing means) 
           59  void portion 
           61  vehicle speed detecting means 
           62  control means 
           63  light source drive circuit 
           70  design panel (display member) 
           71  substrate 
           80 ,  90  diffusing member (diffusing means) 
         L outgoing light 
       
     
       [FIG. 4] 
       [0000]    
       
           61  VEHICLE SPEED DETECTING MEANS 
           62  CONTROL MEANS 
           63  LIGHT SOURCE DRIVE CIRCUIT 
           30  LIGHT SOURCE