Panasonic Corporation

Kosho Suzuki

Takahisa Hatano

Susumu Miura

During adjustment of a white balance, images having different white balances are displayed respectively on a plurality of regions on the screenof the display, based on the red video signal Rout, the green video signal Gout and the blue video signal Bout output from the gamma correction device. After that, an user selects any of the plurality of regions by comparing the plurality of images having the different white balances displayed on the regions A to I on the screenof the displayand pressing a touch panel on the screen. The image on the selected region is displayed on the entire screenof the display, based on the red video signal Rout, the green video signal Gout and the blue video signal Bout output from the gamma correction device

White balance adjusting device and video display device

A PWM generation circuit is set so as to generate a PWM pulse signal having a frequency that is an odd number times a vertical synchronization frequency. A frequency division circuit frequency-divides the PWM pulse signal generated by the PWM generation circuit. An AND gate calculates the logical product of the PWM pulse signal generated by the PWM generation circuit and a frequency-division pulse signal outputted from the frequency division circuit. An OR gate calculates the logical sum of the PWM pulse signal generated by the PWM generation circuit and the frequency-division pulse signal outputted from the frequency division circuit. A selector outputs an output signal of the OR gate as a dimming pulse signal in a case where the set duty ratio is not less than 50%, while outputting an output signal of the AND gate as a dimming pulse signal in a case where the set duty ratio is less than 50%. Consequently, the frequency of the dimming pulse signal is five-second the frequency of a vertical synchronizing signal.

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Hokkaido, Japan

Kosho Suzuki