Electricity controller, device for lighting discharge tube, display device and electric power control method

An electricity controller for controlling output power from a power generator which supplies electric power to a discharge tube filled with discharge gas including argon and mercury,

• said electricity controller comprising a first power control means for controlling output power from said power generator to a first level during a first period of start-up time for feeding,
• a second power control means for controlling output power from said power generator to a second level lower than said first level during a second period after said first period, and
• a third power control means for controlling output power from said power generator to a third level greater than said second level and lower than said first level during a third period after said second period,
• wherein said discharge tube emits infrared ray during said first and second periods, and
• an amount of infrared ray produced during said second period is less than that produced during said first period.

An electricity controller for controlling output power from a power generator which supplies electric power to a discharge tube filled with discharge gas including argon and mercury, said discharge tube being used as a light source for a display,

• said electricity controller comprising a first power control means for controlling output power from said power generator to a first level during a first period immediately after commencement of feeding electric power to said discharge tube, said first period including a non-indicative period of screen for said display,
• a second power control means for controlling output power from said power generator during a second period after said first period, said second period including a non-indicative period of screen for said display, and
• a third power control means for controlling output power from said power generator during a third period after said second period to supply a rated electric power to said discharge tube during said third period for displaying the screen of said display,
• wherein said second power control means repeatedly produces first and second oscillation time spans,
• each power level during the first oscillation time span is greater than mean power level during the third period, and
• each power level during the second oscillation time span is lower than mean power level during the third period.

A lighting device comprising:

• a discharge tube filled with discharge gas including argon and mercury for use in a light source for a display, and
• an electricity controller for controlling output power from a power generator which supplies electric power to said discharge tube,
• said electricity controller comprising:
• a first power control means for controlling output power from said power generator during a first period immediately after commencement of feeding electric power to said discharge tube, said first period including a non-indicative period of screen for said display,
• a second power control means for controlling output power from said power generator during a second period after said first period, said second period including a non-indicative period of screen for said display, and
• a third power control means for controlling output power from said power generator during a third period after said second period to supply a rated electric power to said discharge tube during said third period for displaying the screen of said display,
• wherein said second power control means repeatedly produces first and second oscillation time spans,
• each power level during the first oscillation time span is greater than mean power level during the third period, and
• each power level during the second oscillation time span is lower than mean power level during the third period.

A display device comprising:

• a display,
• a discharge tube filled with discharge gas including argon and mercury, said discharge tube being used as a light source for said display,
• a power generator for supplying electric power to said discharge tube, and
• an electricity controller for controlling output power from said power generator,
• said electricity controller comprising a first power control means for controlling output power from said power generator during a first period immediately after commencement of feeding electric power to said discharge tube, said first period including a non-indicative period of screen for said display,
• a second power control means for controlling output power from said power generator during a second period after said first period, said second period including a non-indicative period of screen for said display, and
• a third power control means for controlling output power from said power generator during a third period after said second period to supply a rated electric power to said discharge tube during said third period for displaying the screen of said display,
• wherein said second power control means repeatedly produces first and second oscillation time spans,
• each power level during the first oscillation time span is greater than mean power level during the third period, and
• each power level during the second oscillation time span is lower than mean power level during the third period.

A method for controlling electric power from a power generator to a discharge tube filled with discharge gas including argon and mercury, said method comprising the steps of:

• firstly controlling output power from said power generator to a first level during a first period of start-up time for feeding to said discharge tube,
• secondly controlling output power from said power generator to a second level lower than the first level during a second period after said first period, and
• thirdly controlling output power from said power generator to a third level greater than the second level but smaller than the first level during a third period after the second period,
• wherein said power generator supplies an enough amount of electric power to said discharge tube during the first period to generate a sufficient amount of mercury vapor in said discharge tube so that the mercury vapor absorbs infrared ray emitted from the discharge gas within said discharge tube during the second period in order to reduce the amount of infrared ray irradiated from said discharge tube.

A method for controlling electric power to a discharge tube filled with discharge gas including argon and mercury, said method comprising the steps of:

• firstly controlling electric power supplied to said discharge tube to a first level during a first period immediately after commencement of feeding electricity to said discharge tube used as a light source of a display, said first period including a non-indicative period of screen on said display,
• secondly controlling electric power supplied to said discharge tube to a second level lower than the first level during a second period including an indicative period of screen on said display after said first period, and
• thirdly controlling electric power supplied to said discharge tube to a third level of a rated electric power during a third period after the second period,
• wherein said second period comprises a first oscillation time span for supplying to said discharge tube electric power of the second level greater than an average level during the third period, and a second oscillation time span for supplying to said discharge tube electric power of the second level lower than an average level during the third period, and
• said first and second oscillation time spans are alternately produced during the second period.