Abstract:
A display member that provides clear and uniform illumination through a light diffusion layer while enabling a wider selection of display colors that can be applied to the part of the display member body not covered by a light-blocking layer in order to clearly identify the uncovered part when the display member is not illuminated. A display member body is covered by a light-blocking layer. Light irradiating the rear side of the display member body illuminates the front side of the display member body through a displaying part that includes a region where the light-blocking layer has not been applied. The display member body provides a light diffusing effect through a light diffusing layer, and includes a specifically colored transparent layer which is applied over the light diffusing layer and which has greater transparency than the light diffusing layer.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an illuminated display member attached to a panel, for example, in an automobile passenger compartment, and a panel display unit to which the display member is attached.  
         [0003]     2. Description of Related Art  
         [0004]     Illumination functions have been incorporated into automotive instrument and display panels to which various devices, such as audio units and the like, are installed. The purpose of the illumination function is to render words and markings on a display member clearly visible at night.  
         [0005]     Japanese Utility Model Patent No. 6-38127 describes a display member that incorporates an illumination function. This display member (described in Japanese Utility Model Patent No. 6-38127 as illumination key (5) is constructed from a transparent resin, or like substance, and is covered with a light-blocking paint layer within which are specifically shaped areas where the paint covering has not been applied.  
         [0006]     When the rear side of this type of display member is illuminated with light, the light is only able to pass through a portion of the display member where there is an absence of paint. Thus, the light becomes visible on the front side of the display member to make the non-painted area clearly visible at night.  
         [0007]     When the display member described in Japanese Utility Model Patent No. 6-38127 is of a uniformly transparent color, there is a significant difference in the intensity of the light passing through portions of the display member closer to the light source, as compared to the light passing through portions farther away from the light source. Moreover, there is the problem of those portions of the display member outside of the light irradiation region seeming to appear transparent, producing a shadow, at certain viewing angles.  
         [0008]     Therefore, it would be preferable to construct the display member from a material able to diffuse light, in order to suppress variations in light intensity, resulting from changes in viewing angle of the non-painted portion, that is, with respect to the visible displaying part of the display member. For example, acrylic resin, ABS resin, other like material, which are of a translucent white color, are preferable.  
         [0009]     Because the non-painted portions on the front of the display member are exposed, they appear as the color of the display member itself during daylight hours, when the display member is not illuminated. It is preferable that the color of the non-painted portions, that is, the portions which are to be illuminated, be clearly differentiated from the color of the paint coating. For example, when the paint coating is a relatively pale color, the color of the display member itself should be dark. Also, for design reasons, there are cases where it is required that a special color be used for the non-painted portion.  
         [0010]     Incidentally, there are restrictions with regard to the type of material that can be used to provide this type of display member body with a light diffusion function. In this respect, there are significant restrictions as to the color of the display member body, i.e., the color of the non-painted portions of the display member when not illuminated. For example, when the display member body is made from acrylic resin, ABS resin, or other like material having a translucent white color as noted previously, the color of the display member is inherently limited to a whitish color.  
         [0011]     In other words, when it is desired that a conventional display member having a light diffusion function be uniformly illuminated, there is a problem in the choice of colors that can be used for the displaying part, i.e., the non-painted portion is significantly restricted if the displaying part is to be clearly visible in a non-illuminated condition.  
       SUMMARY OF THE INVENTION  
       [0012]     One feature of the present invention is to provide a transparent display member body and a light-blocking layer applied to the front surface thereon, in which a displaying part is formed by the absence of the light-blocking layer on a specified portion of the display member body. By irradiating the rear part of the display member body with light and passing the light through the portion not covered by the light-blocking layer, the front of the display member body may be illuminated. The display member body also incorporates a light diffusion layer which has a light diffusion effect, a transparent layer which is applied over the front side of the light diffusion layer, has the degree of color transparency of the transparent layer being greater than that of the light diffusion layer, and is of a specific color. Further, the light diffusion layer is located at least behind the displaying part to cover the part.  
         [0013]     The display member is structured whereby light applied to the rear side of the display member body passes through a light diffusion layer and transparent layer which have been applied to the display member body. The light illuminating the front surface of the display member body passes only through the portion of the display member body to which the light blocking layer has not been applied, thereby resulting in the clear and uniform illumination of the shape of the displaying part, without fluctuations in the light intensity, due to the light diffusion effect provided by the light diffusion layer.  
         [0014]     Moreover, despite restrictions relating to the color of the light diffusion layer (the light diffusion layer being of a translucent white color, for example), the color of the display member body when not illuminated, i.e., the color of the portion not covered by the light-blocking layer, can be established to a desired color, or a color similar to the desired color, by the color of the transparent layer applied over the front surface of the diffusion layer.  
         [0015]     Specifically, the transparent layer of the display member body may be formed as a transparent color film applied over the front of the light diffusion layer. The light diffusion layer and transparent layer may be respectively formed from a light diffusing resin and transparent resin as a single integrated structure (for example, two color molding, coinjection molding, etc.) in order to simplify the display member structure and lower costs through reduced manufacturing procedures.  
         [0016]     The display member may also include a panel, in which a rear side of the display member is illuminated by a light source behind the panel.  
         [0017]     The panel display unit may include the display member in the form of a control part attached to the panel as a portion of the display member (or in the display member), in which the control part is depressably operated from the front of the panel.  
         [0018]     Another feature of the present invention is to provide a display member that includes a transparent display body, a light-blocking layer provided on a front surface of the display body, a displaying portion comprising at least one area on the front surface of the display body that lacks the light-blocking layer, a light diffusion layer provided opposite the displaying portion configured to diffuse light, and a transparent layer of a particular color provided on a second surface of the display body and being more transparent than the light diffusion layer. The displaying portion is illuminated when light illuminates a rear surface of the display member.  
         [0019]     The light diffusion layer may be translucent white. The transparent layer may be adhered to the light diffusion layer or the transparent layer and the light diffusion layer may be a single one-piece structure. The light diffusion layer may be formed of a light diffusing resin and the transparent layer may be formed of a transparent resin.  
         [0020]     Additionally, the rear of the display member is illuminated by a light source behind the panel. The display member includes a control part attached to the panel that is actuated by a depressing operation.  
         [0021]     Due to the presence of the light diffusion layer, the present invention is able to provide uniform display illumination without variations in light intensity. Moreover, in regard to the color of the displaying part when not illuminated, i.e., the part not covered by the light-blocking layer, the use of a transparent color layer applied over the surface of the light diffusion layer widens the selection of the aforesaid color. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     The above, and other objects, features and advantages of the present invention will be made apparent from the following description of the preferred embodiments, given as nonlimiting examples, with reference to the accompanying drawings in which:  
         [0023]      FIG. 1  is an exploded perspective view of a panel display unit according an embodiment of the present invention;  
         [0024]      FIG. 2A  is a front elevation view illustrating the audio control buttons and the holder of the present invention;  
         [0025]      FIG. 2B  is a cross-section view taken along the lines A-A of  FIG. 2A ;  
         [0026]      FIG. 3A  is a detailed cross-sectional view taken along the lines B-B of  FIG. 2A ;  
         [0027]      FIG. 3B  is an enlarged cross-sectional view of circled area C in  FIG. 3A ; and  
         [0028]      FIG. 4  shows a cross-sectional illustration of a modified structure of the control button. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0029]     The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description is taken with the drawings making apparent to those skilled in the art how the forms of the present invention may be embodied in practice.  
         [0030]     The following will describe the preferred embodiments of the invention with reference to the drawings.  FIG. 1  depicts the panel display unit of the present invention embodied in the form of an automotive instrument panel  10 . The instrument panel  10  includes, starting from the top portion down, a CD access orifice  12 , an LCD display orifice  14 , six audio control orifices  16 , and a pair of horizontally disposed rocker switch orifices  18 . A light display orifice  13  is located in proximity to the CD access orifice  12 , one CD control button orifice  20  is located to the left of the CD access orifice  12 , and a pair of CD control button orifices  21  and  22  are located to the right of the CD access orifice  12 . All of the orifices noted above are formed as voids, completely penetrating the front wall portion of the instrument panel  10 .  
         [0031]     The CD control buttons  24 ,  25 , and  26 , and an audio control button  28  extend from the rear of the panel to the front, through the CD control button orifices  20 ,  21 , and  22  and the audio control button orifice  16 , and are thus operable through these orifices. Moreover, a rocker switch cover  78  installs to the rocker switch orifice  18  from the rear of the panel, and rocker switch lever  29  installs to a lever orifice  79  from behind, the lever orifice  79  being integrally formed to the rocker switch cover  78 , thereby allowing the rocker switch lever  29  to pivot forward and backward.  
         [0032]     The CD control buttons  24 ,  25 ,  26 , the audio control button  28 , and the rocker switch cover  78 , are constructed of a transparent material. Of these, the structure and materials of the six audio control buttons  28 , which will be subsequently described, correspond to the display member (and operating member) of the present invention.  
         [0033]     A printed circuit board  30  is located behind the instrument panel  10 . The printed circuit board  30  includes, from the top down, a lamp  31 , a light emitting diode  32 , right and left lamps  34 , six switch elements  36 , and two pairs of switch elements  38 A and  38 B, each pair being vertically disposed at respective left and right locations.  
         [0034]     The lamp  31  serves as the light source for the CD control button  24 , and is positioned accordingly. The light emitting diode  32  is positioned to project light through the light display orifice  13  toward the front side of the panel, and the two lamps  34  serve as light sources positioned to illuminate all of the audio control buttons  28  and the rocker switch cover  78  from the rear. The switch elements  36  are positioned so as to allow their push-in operation through audio control buttons  28 , and the switch elements  38 A and  38 B are positioned so as to allow their push-in operation through the see-saw like pivoting movement of the rocker switch levers  29 . Moreover, although not shown in the drawings, lamps are installed at positions separate from the printed circuit board  30  to illuminate the CD control buttons  25  and  26 .  
         [0035]     Although not shown in the drawings, the printed circuit board  30  also includes an LCD (liquid crystal display) which inserts into LCD display orifice  14  from behind.  
         [0036]     A light guide holder  40  is placed between the printed circuit board  30  and CD control button  24 . The light guide holder  40  is equipped with the light guide support parts  42 ,  43 , and  44  which are located directly behind the CD control buttons  24 ,  25 , and  26 , a light guide support part  46  which is located directly behind light orifice  13 , and a CD access window  48  which is located directly behind the CD access orifice  12 . The light guide support parts  42 ,  43 ,  44 , and  46 , and a CD access window  48 , are formed as voids which penetrate the light guide holder  40 . Moreover, a CD felt material  50  is installed around the perimeter of the CD access window  48  so as to come into contact with a CD (compact disc) when the CD passes through the CD access window  48 .  
         [0037]     A light guide  52  is supported by the light guide support part  42 , a light guide  54  is supported by the light guide support parts  43  and  44 , and the light guide  56  is supported by the light guide support part  46 .  
         [0038]     The light guide  52  directs the light emitted by the lamp  31  toward the rear part of the CD control button  24 , is entirely made from a relatively transparent material which may be acrylic resin or the like, and includes a lens  52   a  which is a more thickly formed part that extends forward (toward the panel) at a predetermined position. The lens  52   a  is inserted into the light guide support part  42  from the rear, and is thus supported by the light guide holder  40 .  
         [0039]     In the same manner, the light guide  54  directs light emitted from a lamp (not shown in the drawings) to the rear side of the CD control buttons  25  and  26 , is made from a relatively transparent material which may be acrylic resin or the like, and includes the lenses  54   a  and  54   b  which are more thickly formed parts that extend forward (toward the panel). The lenses  54   a  and  54   b  are inserted into the light guide support parts  43  and  44 , respectively from the rear, and are thus supported from the rear by the light guide holder  40 .  
         [0040]     Additionally, the light guide  56  directs light emitted from the light emitting diode  32  to the external area through the light display orifice  13 , is made entirely from a relatively transparent material which may be acrylic resin or the like, and is inserted into the light guide support part  46  from the rear, and is thus supported by the light guide holder  40 .  
         [0041]     A holder unit  60  is installed between the printed circuit board  30  and the audio control buttons  28 , and between the printed circuit board  30  and the rocker switch levers  29 .  
         [0042]     The holder unit  60  includes a light guide support part  62 , actuator support parts  64  and  66 , and a light guide support part  68 .  
         [0043]     The light guide support part  62  is installed directly behind each audio control button  28 , and the light guide support part  68  is installed directly behind the rocker switch cover  78 . An actuator support part  64  is installed directly beneath each light guide support part  62  opposing the switch elements  36  on the printed circuit board  30 , and actuator support parts  66  are installed in respective opposition to the switch elements  38 A and  38 B directly behind each rocker switch lever  29 .  
         [0044]     A lever support wall  67 , which protrudes from the front of the holder unit  60 , supports the rocker switch lever  29  so as to allow its pivoting movement forward and backward.  
         [0045]     A light guide  70  is supported by each light guide support part  62 , and each actuator  74  is supported by a corresponding actuator support part  64 .  
         [0046]     The light guide  70 , which directs light emitted from the lamps  34  to the rear side of each audio control button  28  and rocker switch cover  78 , is made of a comparatively transparent acrylic resin or other like material. To be more specific, the light guide  70 , as shown in  FIG. 2B , includes a main part  71  which extends horizontally to the left and right, thickly formed lenses  72  which extend upward from the front portion of the main part  71 , and lenses  73  (as shown in  FIG. 1 ) that extend downward and then forward from the main part  71 . The main part  71  and the lenses  72  and  73  are integral to the light guide  70 . The lenses  72  and  73  are respectively inserted into the light guide support parts  62  and  68  from behind, thus creating a structure whereby the light guide  70  is completely supported by the light guide holder  40 .  
         [0047]     Operating pressure applied to an audio control button  28  is transferred to a corresponding switch element  36  (located behind the lower edge of the audio control button  28 ) via actuator  74 , each actuator  74  being formed as a pin-shaped member movably supported in the axial direction by the actuator support part  64  of the holder unit  60 . In a similar manner, the pivoting movement of the rocker switch lever  29  in the forward and backward directions, effected by operating pressure applied thereto, is conveyed to the switch element ( 38 A or  38 B) via actuator  76 , each actuator  76  being movably supported in the fore-aft direction by the actuator support part  66 .  
         [0048]     In this type of panel display unit, the CD control button  24  is illuminated by the mechanism through which the lens  52   a  of the light guide  52  conveys light from the illuminated lamp  31  of the printed circuit board  30  to the CD control button  24 . In a similar manner, the CD control buttons  25  and  26  are illuminated by the mechanism through which the lenses  54   a  and  54   b  of the light guide  54  convey light from an illuminated lamp (not shown in the drawings) to the CD control buttons  25  and  26 . Additionally, the light guide  56  conveys light emitted from the light emitting diode  32  to the front of the panel at the light display orifice  13 . Furthermore, the audio control buttons  28  are illuminated by light emitted from the lamps  34  being conveyed to each audio control button  28  through each lens  72  of the light guide  70 , and the rocker switch covers  78  are illuminated by the light emitted from the lamps  34  being conveyed to each rocker switch cover  78  through each lens  73  of the light guide  70 .  
         [0049]     Pressure applied to the audio control button  28  is conveyed to the switch element  36  through the actuator  74 , thus switching the switch element  36  to an ON state. Also, the pivoting movement of the rocker switch lever  29  is conveyed to a corresponding switch element ( 38 A or  38 B) through the actuator  76  when the rocker switch lever  29  is pivotally operated in either the forward or backward direction, thus switching that switch element to an ON state.  
         [0050]     The following will provide a detailed description, with reference to  FIGS. 2A, 2B ,  3 A and  3 B, of the present invention, as embodied in the structure of the audio control buttons  28 .  
         [0051]     The audio control buttons  28 , a support member  80 , and thin hinge parts  82  are formed as a single integrated structure of synthetic resin in which the control buttons  28  are connected, in horizontal alignment, to the common support member  80  through the thin hinge parts  82 . With the support member  80  fixedly installed to the rear of the instrument panel  10 , each audio control button  28  may be individually pressed and thereby moved through the distortional flexing of the hinge part  82 .  
         [0052]     As shown in  FIG. 3B , each audio control button  28  is structured as a button body  84  (a body of the display) on which a covering of a light-blocking paint (an opaque layer)  86  has been applied.  
         [0053]     The button body  84  is structured to include a light diffusion layer  87  over which a transparent layer  88  is applied to the front-facing surface thereon. The light diffusion layer  87  provides a light diffusion effect that diffuses the light from the lens  72  of the light guide  70  over the complete button. The diffusion layer  87  may be formed from a transparent resin, such as an acrylic or polycarbonate resin, into which diffusion particles have been mixed to obtain a translucent white color, or from a material which is a naturally translucent white color, such as ABS resin. The transparent layer  88 , which has greater transparency than the light diffusion layer  87 , may be formed from a transparent resin, such as the aforesaid acrylic resin or polycarbonate resin, into which coloring particles (of a black color, for example) are mixed to obtain the desired color density.  
         [0054]     The light diffusion and transparent layers  87  and  88  may be formed as a single structure by two color molding, or may be formed as a structure in which a transparent colored film is adhered to the top of the diffusion layer  87 .  
         [0055]     A paint layer  86  is formed of an opaque light-blocking paint applied over the transparent layer  88  wherein missing portions of the paint layer  86  have contours formed in the shapes of numbers, letters, and various markings. In other words, a non-painted portion  85  (e.g., the above-noted missing portions) becomes the displaying part by exposing the surface of the transparent layer  88 .  
         [0056]     Specifically, the thickness of the paint layer  86 , diffusion layer  87 , and transparent layer  88  may be established as appropriately required, but generally speaking, a thickness of 30 μm for the paint layer  86  and 0.7˜1.2 mm for the diffusion layer  87  and transparent layer  88  is appropriate.  
         [0057]     Moreover, the light-blocking layer need not be of paint as specified in this embodiment, but may, for example, be a highly opaque material, such as a film or other like material, in which specific portions have been cut out and attached to the surface of the button body  84 .  
         [0058]     Furthermore, the light diffusion layer  87  need not be applied over the entire surface of the button body  84 , but may be provided only in the region behind the non-painted portion  85  so that the light diffusion effect illuminates only the portion to which no paint has been applied. As shown by the structure of the control button  28 ′ in  FIG. 4 , for example, the diffusion layer  87  may be provided at only one portion of the button body  84 .  
         [0059]     Because the above-described structure conveys the light in the lenses  72  to the audio control buttons  28  through the light diffusion layer  87  and transparent layer  88  formed on each button body  84 , therefore allowing light to pass only through the non-painted portion  85  where the paint layer  86  has not been applied, the light diffusion effect provided by the light diffusion layer  87  allows the distinct and uniform illumination of the shape of the non-painted portion  85  with minimal fluctuation in light density. Moreover, even though the composition of the light diffusion layer  87  may be limited to that which provides a translucent white appearance, the color of the non-illuminated button body  84 , that is, the color of the non-painted portion  85 , may be established as a desired color, or a color close to a desired color, by adding color to the transparent layer  88  applied over the diffusion layer  87 . Therefore, even though the paint layer  86  may be of a comparatively pale color, establishing the non-painted portion  85  as a comparatively dark color will result in clearly defined display of the non-painted portion  85  under both illuminated and non-illuminated conditions.  
         [0060]     While the display member invention has been described in reference to the audio control buttons  28  shown in  FIGS. 1, 2A ,  2 B,  3 A, and  3 B other control components, such as the CD control buttons  24 ,  25 , and  26 , and the rocker switch lever  29 , may be structured according to the precepts of the present invention. Furthermore, the components to which the present invention may be applied are not limited to the control buttons described in this specification, but may also include, for example, the rocker switch cover  78  illustrated in  FIG. 1 .  
         [0061]     Furthermore, the present invention is not limited to a panel display unit embodied as the automotive instrument panel  10  shown in  FIG. 1 , but may also be incorporated into display panels installed in various types of electronic devices, such as audio products, or buildings and the like.  
         [0062]     The present disclosure relates to subject matter contained in priority Japanese Application No. 2004-157897, filed on May 27, 2004, which is herein expressly incorporated by reference in its entirety.  
         [0063]     Although the invention has been described with reference to an exemplary embodiment, it is understood that the words that have been used are words of description and illustration, rather than words of limitation. Changes may be made within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the invention in its aspects. Although the invention has been described with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed. Rather, the invention extends to all functionally equivalent structures, methods, and uses such as are within the scope of the appended claims.