Switch, keyboard instrument provided with the same, and light emission control circut
AssigneeKabushiki Kaisha Kawai Gakki Seisakusho
InventorKenji Kamada
Life of this patent
Estimating the term…
Abstract
A switch according to the present invention includes: a substrate; a touch sensor; a light guide plate; a light emitting unit; and a control unit. The light guide plate has a surrounding side surface chamfered so that a light entering into the surrounding side surface of the light guide plate diffusely reflects inside the light guide plate. The light emitting unit is arranged at a position facing the surrounding side surface of the light guide plate. The light emitting unit is configured to emit the light to the surrounding side surface of the light guide plate.
Claims14
A switch comprising:
- a substrate;
- a touch sensor mounted on the substrate and configured to detect an operator's touch operation relative to the switch;
- a light guide plate stacked on the touch sensor and having a chamfered surrounding side surface so that light entering into the chamfered surrounding side surface of the light guide plate diffusely reflects inside the light guide plate;
- a light emitting unit mounted on the substrate and arranged at a position facing the chamfered surrounding side surface of the light guide plate, the light emitting unit being configured to emit the light to the chamfered surrounding side surface of the light guide plate;
- and
- a control unit configured to control a light emission of the light emitting unit in accordance with a detection result of the touch sensor for detecting the operator's touch operation.
A keyboard instrument comprising a switch, and the switch comprising:
- a substrate;
- a touch sensor mounted on the substrate and configured to detect an operator's touch operation relative to the switch;
- a light guide plate stacked on the touch sensor and having a chamfered surrounding side surface, so that light entering into the chamfered surrounding side surface of the light guide plate diffusely reflects inside the light guide plate;
- a light emitting unit mounted on the substrate and arranged at a position facing the chamfered surrounding side surface of the light guide plate, the light emitting unit being configured to emit the light to the chamfered surrounding side surface of the light guide plate;
- and
- a control unit configured to control a light emission of the light emitting unit in accordance with a detection result of the touch sensor for detecting the operator's touch operation.
A light emission control circuit comprising:
- a first light source and a second light source connected in series each other between a predetermined voltage applied point and a predetermined ground point;
- a voltage applying circuit configured to apply a driving voltage enabling one of the first light source and the second light source to turn on between the voltage applied point and the ground point;
- a control element having an output terminal connected between the first light source and the second light source and configured to operate by the driving voltage;
- and
- a control circuit configured to control the control element;
- wherein the control element is configured to switch a voltage of the output terminal among the driving voltage, a ground voltage being a voltage at the ground point, and a voltage lower than the driving voltage and higher than the ground voltage.
Dependencies are inferred from the claim text.