Abstract: A display device includes a liquid crystal panel and a light source that emits light onto the liquid crystal panel, the display device including: a video signal obtainer that obtains a video signal; a visible light signal obtainer that obtains a visible light signal; a panel controller that drives the liquid crystal panel at a predetermined frequency according to the video signal obtained; and a light source controller that repeats, in a predetermined cycle, a first control for causing a luminance change in the light source according to the visible light signal. The light source controller synchronizes a control for repeating the first control with a cycle for driving the liquid crystal panel by the panel controller.

Abstract: A display device includes a liquid crystal panel and a light source that emits light onto the liquid crystal panel, the display device including: a video signal obtainer that obtains a video signal; a visible light signal obtainer that obtains a visible light signal; a panel controller that drives the liquid crystal panel at a predetermined frequency according to the video signal obtained; and a light source controller that repeats, in a predetermined cycle, a first control for causing a luminance change in the light source according to the visible light signal. The light source controller synchronizes a control for repeating the first control with a cycle for driving the liquid crystal panel by the panel controller.

Abstract: A semiconductor light source control apparatus includes a semiconductor light source that emits light in accordance with a current, a detection resistor that generates a detection voltage by the current flowing in the semiconductor light source; and a power supply current control apparatus that controls the current flowing in the semiconductor light source based on the detection voltage. The semiconductor light source control apparatus pulse-width-modulates (PWM) the current flowing in the semiconductor light source for respective ones of a plurality of color intervals to adjust brightness and color tone of output light from the semiconductor light source. An amplitude of the current flowing in the semiconductor light source is controlled only in a predetermined color interval when a duty value of the PWM is maximum.

Abstract: A semiconductor light source control apparatus includes a semiconductor light source that emits light in accordance with a current, a detection resistor that generates a detection voltage by the current flowing in the semiconductor light source; and a power supply current control apparatus that controls the current flowing in the semiconductor light source based on the detection voltage. The semiconductor light source control apparatus pulse-width- modulates (PWM) the current flowing in the semiconductor light source for respective ones of a plurality of color intervals to adjust brightness and color tone of output light from the semiconductor light source. An amplitude of the current flowing in the semiconductor light source is controlled only in a predetermined color interval when a duty value of the PWM is maximum.

Abstract: In a discharge lamp ignition apparatus, a control circuit unit: lowers a drive frequency from a predetermined initial frequency; establishing, if a resonant voltage reaches an ignition voltage for igniting a discharge lamp, a drive frequency at the ignition voltage as a discharge-lamp-ignition drive frequency which is a frequency for igniting the discharge lamp; and sets, if the resonant voltage does not reach the ignition voltage even though the drive frequency is lowered from the predetermined initial frequency to a resonant frequency, a frequency which is a predetermined value higher than the drive frequency at a resonant voltage peak voltage as the discharge-lamp-ignition drive frequency, and an inverter circuit unit alternating-current drives the resonant circuit unit at the discharge-lamp-ignition drive frequency established by the control circuit unit.

Abstract: In a discharge lamp ignition apparatus, a control circuit unit: lowers a drive frequency from a predetermined initial frequency; establishing, if a resonant voltage reaches an ignition voltage for igniting a discharge lamp, a drive frequency at the ignition voltage as a discharge-lamp-ignition drive frequency which is a frequency for igniting the discharge lamp; and sets, if the resonant voltage does not reach the ignition voltage even though the drive frequency is lowered from the predetermined initial frequency to a resonant frequency, a frequency which is a predetermined value higher than the drive frequency at a resonant voltage peak voltage as the discharge-lamp-ignition drive frequency, and an inverter circuit unit alternating-current drives the resonant circuit unit at the discharge-lamp-ignition drive frequency established by the control circuit unit.

Abstract: A discharge lamp lighting apparatus of the present invention comprises: a power supply section for supplying a discharge lamp voltage prescribed in accordance with the characteristic of the discharge lamp; an inverter for inversely converting the discharge lamp voltage supplied by the power supply section into an AC voltage to be applied to the discharge lamp; and a control section for controlling the discharge lamp voltage in the power supply section and a drive frequency in the inverter, based on the AC voltage applied to the discharge lamp and an AC current flowing in the discharge lamp.