Patent ID: 8772684
Filing Date: 2014-07-08
Classification: F24C

Abstract:
1. A heating cooker comprising: an optically-transparent top plate provided as a top face of an appliance; a heating unit formed beneath the top plate; electrostatic touch keys defined in the top plate and respectively assigned different functions to be performed including a lock release function, the electrostatic touch keys comprising electrodes arranged on a lower face of the top plate in alignment, respectively, with the electrostatic touch keys, the electrodes each being formed of a light-blocking conductive coating which is partially removed in a shape representative of a graphical or character image; an operation detecting unit configured to detect an operation of the respective electrostatic touch keys, wherein the operation detection unit applies an alternating current signal to the respective electrodes and detects a change in a capacitance between the respective electrodes and a ground, which is caused by a contact by a user with the top plate at a location of the respective electrodes; operation unit illuminators arranged in alignment, respectively, with the electrostatic touch keys to irradiate the electrostatic touch keys with light in a direction towards the top plate; an illumination controller configured to turn on one of the operation unit illuminators to irradiate a corresponding electrostatic touch key to project the image formed by the electrode of the corresponding touch key so that the projected image is visible through the top plate and turn off the one operation unit illuminator to make the image less visible through the top plate; and a lighting failure detector configured to detect a break-down of a light source of an operation unit illuminator; and a display unit configured to display an error, when the lighting failure detector detects that an operation unit illuminator fails to light up, to inform the user of the failure of the operation unit illuminator, wherein, upon being powered on, the heating cooker enters into a lock state in which only an electrostatic touch key assigned with the lock release function is operable among the electrostatic touch keys, and the illumination controller has only one of the operation unit illuminators turned on to irradiate the electrostatic touch key assigned with the lock release function in order to guide the user to contact the top plate at a location corresponding to the electrostatic touch key with the lock release function, and further wherein when the operation detecting unit detects an operation of the electrostatic touch key with the lock release function, the illumination controller has at least one of the operation unit illuminators turned on to irradiate at least one of the electrostatic touch keys, other than the electrostatic touch key with the lock release function, which is supposed to be operable subsequent to an operation of the electrostatic touch key with the lock release function, while having turned off any operation unit illuminators for any remaining electrostatic touch keys which are supposed to be inoperable subsequent to an operation of the electrostatic touch key with the lock release function.