Abstract:
A luminous keyboard module uses a luminous material to produce keys of the keyboard module, or uses the luminous material to produce a backlight plate under the keys. When an UV light source irradiates UV light on the keys or the backlight plate containing the luminous material, the keys or the backlight plate can illuminate visible light to show the character symbols on the corresponding keys clearly under environment with insufficient light.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to Taiwan Application Serial Number 95122830, filed Jun. 23, 2006, which is herein incorporated by reference. 
       BACKGROUND 
       [0002]    1. Field of Invention 
         [0003]    The present invention relates to an input device. More particularly, the present invention relates to a luminous keyboard module. 
         [0004]    2. Description of Related Art 
         [0005]    Under an environment with insufficient light, such as a laboratory, a coffee shop, or a meeting room, character symbols on keys of a notebook computer keyboard are hard to be recognized. Many solutions have been provided to solve this problem. 
         [0006]    In one solution, a reading light is mounted on a monitor of a notebook computer. Although the production cost is low, battery lifetime is reduced because power is also consumed by the reading light. Moreover, the illuminating angle of the reading light needs to be adjusted to avoid light directly illuminating on viewer&#39;s eyes. Furthermore, it is preferable to have light-colored character symbols on deep-colored keys so character symbols are easily visualized. 
         [0007]    In another solution, a fluorescent paint is used to print character symbols on the keys of the notebook computer. Therefore, fluorescent paint can be irradiated with regular light and fluorescence will thus be generated from character symbols of keys. Although the production cost is low and the additional processing is simple, the intensity of the fluorescence is limited and the key surfaces as well as character symbols are easily scratched. 
         [0008]    In yet another solution, one or more LEDs are used as light sources. Light generated by LEDs is conducted by many optical fibers disposed in a keyboard to light up the whole keyboard. Although its light intensity and lifetime are acceptable, lower mechanical strength of the keyboard is unavoidable due to holes in the keyboard are necessary for light propagation. Moreover, the height of the keyboard and the production cost are increased. That is why this solution is not popular. 
         [0009]    In yet another solution, an electroluminescent (EL) material can be used as a light source. The features include power saving, higher light intensity, simple additional processing, cheap cost, and high impact toughness. However, the lifetime of the EL material is reduced due to high working temperature of the notebook computer, and the production cost is increased due to extra driving circuits required for EL material. Moreover, EL material usually contains phosphorous which causes environmental pollution problems. 
         [0010]    In yet another solution, LEDs are disposed in four corners of the keyboard, and a light guide plate is used to guide light generated by the LEDs. Light can be softened and the structure of light guide plate is simple. However, holes are also required in the keyboard to allow light propagation, and longer adjusting time in product development is needed to obtain a uniform light intensity over the keyboard. 
         [0011]    In yet another solution, each key has a LED therein as the light source. Although light intensity is strong, but many light spots are produced to irritate user&#39;s eyes. Moreover, the production cost is greatly increased, and more power is consumed by LEDs. 
       SUMMARY 
       [0012]    According to an embodiment, a luminous keyboard module is provided. The luminous keyboard module comprises a base, keys disposed on the base, and a light source positioned to illuminate UV light on the keys. Each of the keys has a corresponding character symbol thereon, and the character symbol is made by a luminous material. The UV light generated by the light source illuminates on the keys to enable the luminous material to irradiate visible light. The light source can be disposed on a monitor or a body of a computer. 
         [0013]    According to another embodiment, another luminous keyboard module is provided. The luminous keyboard comprises a base, keys disposed on the base, a backlight plate disposed between the base and the keys, and a light source disposed in the base and positioned to illuminate UV light on the backlight plate. The light source can be disposed under the backlight plate or on a lateral side of the backlight plate. The UV light generated by the light source illuminates on the backlight plate containing a luminous material to enable the luminous material to irradiate visible light. 
         [0014]    It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
           [0016]      FIG. 1A  is a diagram showing a luminous keyboard module applied on a notebook computer according to an embodiment of this invention; 
           [0017]      FIG. 1B  is a local cross-sectional view of the luminous keyboard module in  FIG. 1A ; 
           [0018]      FIG. 1C  is a local top-view of the luminous keyboard module in  FIG. 1A ; 
           [0019]      FIG. 2A  is a local cross-sectional diagram of another luminous keyboard module according to another embodiment of this invention; and 
           [0020]      FIG. 2B  is a local cross-sectional diagram of another luminous keyboard module according to another embodiment of this invention. 
       
    
    
     DETAILED DESCRIPTION 
     Embodiment 1 
       [0021]      FIG. 1A  is a diagram showing a luminous keyboard module applied on a notebook computer according to an embodiment of this invention. In  FIG. 1A , a notebook computer  500  comprises a bottom housing  501 , which comprises a motherboard, a central processing unit, and etc., a monitor  502 , and a luminous keyboard module  100 . 
         [0022]      FIG. 1B  is a local cross-sectional view of the luminous keyboard module in  FIG. 1A , and  FIG. 1C  is a local top-view of the luminous keyboard module in  FIG. 1A . In  FIGS. 1B and 1C  the keyboard module  100  comprises a base  101 , plural keys  102  and a light source  104 . The base  101  is disposed in the bottom housing  501  (in  FIG. 1A ), and the keys  102  are disposed on the base  101 . 
         [0023]    Each key  102  has a corresponding character symbol  103  thereon. The character symbols  103  can be made by a luminous material, such as a fluorescent material, a phosphorescent material, or a combination thereof. For example, the fluorescent material can be a stilbene compound or a derivative thereof; the phosphorescent material can be a sulfide compound such as ZnS. 
         [0024]    The keys  102  having the character symbols  103  made by luminous material can be manufactured by bi-injection molding. Since the luminous material is a part of the keys  102 , rather than print on the keys, the character symbols  103  are durable and can be recognized easily. 
         [0025]    The light source  104  can be mounted on any place that can illuminate UV light on the keys  102  to enable the luminous material to irradiate visible light. For example, the light source  104  can be mounted on the top or right/left side of the monitor  502  (in  FIG. 1A ), or at any suitable place in the bottom housing  501 . The light source  104  can generate UV light with wavelengths of 320-400 nm (UV-A). In one embodiment, the light source can generate UV light in wavelengths of 360-380 nm. 
         [0026]    The light source  104  can be a black-light tube, a type of small UV tube, or an UV LED. For example, the black-light tube can be a commercial product, F4T5/BLB, manufactured by Philips or Osram; the UV LED can be a commercial product NSHU550A, NSHU590A, NSHU550B, or NSHU550B manufactured by Nichia. The harmful UV light (UV-B, in 280-320 nm, and UV-C, less than 280 nm) can be filtered by a plating layer in the UV tube or a package material of the LED. 
         [0027]    Therefore, under such arrangement, the character symbols  103  on the keys  102  can irradiate visible light under the UV light generated by the light source  104 . User can recognize the character symbols  103  very easily under an environment with insufficient light. 
       Embodiment 2 
       [0028]      FIGS. 2A-2B  are local cross-sectional diagrams of another two various luminous keyboard modules according to another embodiment of this invention. In  FIGS. 2A-2B , the keyboard module  200  or  200 ′ includes a base  201 , a backlight plate  202 , a light source  203   a  or  203   b , and plural keys  204 . 
         [0029]    The backlight plate  202  is disposed in the base  201  and positioned under the keys  204 . The light source  203   a  or  203   b  can be disposed in the base  201  and positioned under the backlight plate  202 , as shown in  FIG. 2A , or positioned on a lateral side of the backlight plate  202 , as shown in  FIG. 2B . The keys  204  are disposed on the base  201 . Each key  204  has at least an opaque cap  204  and a transparent character symbol  206 , which can be made by bi-injection molding. 
         [0030]    The raw materials of the backlight plate  202  include a luminous material, such as a fluorescent material, a phosphorescent material, or a combination thereof. For example, the fluorescent material can be a stilbene compound or a derivative thereof; the phosphorescent material can be a sulfide compound, such as ZnS. The luminous material can be blended into a matrix material, such as a polymer or other suitable materials, and then form the backlight plate  202 . If the matrix material is a polymer, such as an acrylic resin, the backlight plate  202  can be made by injection molding. 
         [0031]    The light source  203   a  or  203   b  can be a black-light tube, a type of small UV tube, or an UV LED. For example, the black-light tube can be a commercial product, F4T5/BLB, manufactured by Philips or Osram; the UV LED can be a commercial product NSHU550A, NSHU590A, NSHU550B, or NSHU550B manufactured by Nichia. The harmful UV light (UV-B, in 280-320 nm, and UV-C, less than 280 nm) can be filtered by a plating layer in the UV tube or a package material of the LED. 
         [0032]    Since the backlight plate  202  comprises a luminous material, the backlight plate  202  can irradiate visible light under the UV light illumination of the light source  203   a  or  203   b . The visible light irradiated by the backlight plate  202  can then penetrate the transparent character symbols  206  of the keys  204 . Hence, user can recognize the character symbols  206  clearly under environment with insufficient light. 
         [0033]    According to the embodiments of this invention, several luminous keyboard modules are provided to allow user to easily recognize the character symbols of the keys under environment with insufficient light without increasing much production cost. 
         [0034]    It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims.