Abstract: A characteristic value-calculating unit, calculating a characteristic value based on an input image signal, a conversion characteristic-calculating unit, determining a conversion characteristic from the characteristic value, and a signal-converting unit, converting the input image signals in accordance with the determined conversion characteristic, are provided. The conversion characteristic has a low level region segment, which is close to the origin, a high level region segment, which is close to a full scale point, and a middle level region segment, which is positioned between the low level region and high level region, and the slope in the middle level region is set so as to be larger than both of the slopes of the low level region and the high level region.

Abstract: A display controller including a video signal-analyzing unit, a video signal-adjusting unit operable to receive a video signal, to adjust the video signal in accordance with adjustment parameter information, and to feed the adjusted video signal into a display device, and a light source-controlling unit operable to feed a light source-controlling signal into a light source in accordance with light source light-emitting amount information. The video signal-analyzing unit allows timing in which the display device displays a picture in accordance with the adjusted video signal from the video signal-adjusting unit to be synchronized with timing in which the light source changes a light-emitting amount in response to the light source-controlling signal from the light source-controlling unit.

Abstract: There is provided a correlation between adjustment of luminance of a LCD and adjustment of luminance of a backlight. Luminance average value “Iave” is determined from display data. Luminance maximum value “I1max” in a macro area is determined from the display data. Luminance is adjusted with reference to luminance-transformed luminance. In luminance transformation, slope average “r1” in a range of 0≦I<Iave, slope average “r2” in a range of Iave≦I<I1max, and slope average “r3” in a range of I≧I1max establish a relationship of r1≧r2>r3 in an area defined by a horizontal axis showing luminance “I” and a vertical axis showing luminance-transformed luminance “I#”.

Abstract: A fold-up mobile terminal device comprising a lower case having a key operating portion, an upper case having a display portion, a coupling portion which makes the lower case and upper case rotatable, and a turnover preventing portion. The turnover preventing portion is attached to the rear of the upper case, which is the direction where a turnover is most likely to occur, in a direction approximately the same as that of a supporting surface of the lower case.