Illuminating structure of key operating unit, electronic apparatus, portable apparatus, and illuminating method of key operating unit

1. An illuminating structure of a key operating unit for operating a key switch, comprising:

a housing unit to have a window portion formed correspondingly to the key switch;

a circuit substrate to be provided inside the housing unit, to be disposed with the key switch, and to be provided with a light-guiding window portion;

a keypad unit to include a plurality of key top portions inserted in the window portion of the housing unit, the keypad unit including a light-guiding portion at least in a plurality of the key top portions;

a light-emitting element to be arranged on a back surface side of the circuit substrate; and

an illuminating plate to have a reflecting portion, having a reflecting surface across a plurality of the key top portions, reflecting outgoing light of the light-emitting element by the reflecting surface to apply the reflected light from the reflecting portion to a plurality of the key top portions through the light-guiding window portion of the circuit substrate.

2. The illuminating structure of the key operating unit of claim 1 , wherein the illuminating plate includes a recess portion and includes the reflecting portion in the recess portion.

3. The illuminating structure of the key operating unit of claim 2 , wherein the light-emitting element is inserted in the recess portion.

4. The illuminating structure of the key operating unit of claim 1 , further comprising a dome sheet to cover the key switch.

5. The illuminating structure of the key operating unit of claim 4 , further comprising a light-guiding window portion to allow passage of the reflected light through the dome sheet.

6. The illuminating structure of the key operating unit of claim 4 , further comprising a projecting portion corresponding to a key dome of the dome sheet on a back surface portion of the keypad unit.

7. The illuminating structure of the key operating unit of claim 1 , wherein the illuminating plate makes up a shield case unit of a circuit device disposed on a back surface side of the illuminating plate.

8. The illuminating structure of the key operating unit of claim 7 , further comprising a surrounding wall portion to surround functional units of the circuit device on a side portion of a back surface of the illuminating plate.

9. The illuminating structure of the key operating unit of claim 8 , wherein a shield member shielding the circuit substrate side and the functional units is disposed in a space unit surrounded by the surrounding wall.

10. The illuminating structure of the key operating unit of claim 1 , wherein the reflecting portion includes another reflecting surface to reflect the reflected light that is reflected by the reflecting surface.

11. The illuminating structure of the key operating unit of claim 1 , wherein the illuminating plate is made of a shield member for shielding a noise.

12. An electronic apparatus having a key operating unit of a key switch, comprising:

a housing unit to have a window portion formed correspondingly to the key switch;

a circuit substrate to be provided inside the housing unit, to be disposed with the key switch, and to be provided with a light-guiding window portion;

a keypad unit to include a plurality of key top portions inserted in the window portion of the housing unit, the keypad unit including a light-guiding portion at least in a plurality of the key top portions;

a light-emitting element to be arranged on a back surface side of the circuit substrate; and

an illuminating plate to have a reflecting portion, having a reflecting surface across a plurality of the key top portions, reflecting outgoing light of the light-emitting element by the reflecting surface to apply the reflected light from the reflecting portion to a plurality of the key top portions through the light-guiding window portion of the circuit substrate.

13. The electronic apparatus of claim 12 , wherein the electronic apparatus is a portable apparatus.

14. An illuminating method of a key operating unit for operating a key switch, comprising:

forming a window portion corresponding to the key switch in a housing unit;

disposing the key switch and forming a light-guiding window portion on a circuit substrate provided inside the housing unit;

forming a plurality of key top portions on a keypad unit for pressing down the key switch and inserting a plurality of the key top portions in the window portion of the housing unit;

arranging a light-emitting element on a back surface side of the circuit substrate; and

forming a reflecting portion, having a reflecting surface across a plurality of the key to portions, reflecting outgoing light of the light-emitting element by the reflecting surface to apply the reflected light acquired by the reflecting portion to a plurality of the key to portions through the light-guiding window portion of the circuit substrate.

15. The illuminating method of the key operating unit of claim 14 , wherein a recess portion is formed in the illuminating plate and wherein the reflecting portion is formed in the recess portion.

16. The illuminating method of the key operating unit of claim 15 , wherein the light-emitting element is inserted in the recess portion.