| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive display device having improved visibility with high-luminance emission while preventing the occurrence of emission luminance spots on a dial and achieving higher emission illuminance particularly in a high speed region than in other regions by using an inexpensive light guide which efficiently uses the light quantity of a light source for lighting to achieve higher emission illuminance in a desired region than in other regions. <P>SOLUTION: Light from the light source 9 is input to a planarly circular light guide plate 5 of the light guide 7 arranged on the backside of the dial 3. The input light is reflected toward the dial 3 by reflecting faces 21A of a plurality of light reflecting grooves 21 formed radially from the center position of the light guide plate 5. At this point, the light guide plate 5 of the light guide 7 is set in at least two regions 23, 25, and the light reflecting grooves 21 of the regions 23, 25 are formed mutually different to give a high-low illuminance difference between the regions 23, 25. The reflected light is transmitted through scale portions 15 and digit portions 17 of the dial 3 to be lit. <P>COPYRIGHT: (C)2010,JPO&INPIT |
