The present invention relates to a method of generating an image having a desired brightness, which image is generated by means of a device provided with at least one light source, at least one electro-optical light modulation panel and at least one light-control device. The light from the light source is converted into an image having a desired brightness via at least the electro-optical light modulation panel and the light-control device. The image to be projected is analyzed in a regulator, whereafter the electro-optical light modulation panel and the light-control device are driven, while a too bright image is generated by means of the electro-optical light modulation panel, which image is converted by means of the light-control device into an image having a desired brightness and a desired contrast.

The invention provides a display panel 9; a gain variable liquid crystal driving circuit 10 for driving the display panel 9; a backlight operating circuit 6 for operating, based on a lamp control signal, a backlight 8 for illuminating the display panel 9; a level extension signal calculating circuit 11 for outputting an optical output level extension signal Lout by extending a predetermined output level used to operate the backlight 8; and a white peak improving circuit 5 for receiving the optical output level extension signal, and for outputting a lamp control signal, whose white peak level has been adjusted according to a change in brightness of a scene and for calculating and outputting a video amplitude gain as a coefficient to a gain variable driving amplifier circuit 3, wherein the lamp control signal is outputted when the brightness of a scene is above normal level, and the video amplitude gain is outputted when the brightness is at normal level.

A display apparatus having a control unit which controls the light source temperature so that the temperature remains within a predetermined temperature range, a light modulation device for displaying images by receiving light emitted from the light source, and modulating the light according to the image data, and a light source controlling unit which adjusts the amount of light that enters the light modulation device, by controlling electrical power fed to the light source, according to the brightness data. Even if a contrast ratio is improved by changing the amount of light of an HID lamp, a passive optical modulation type display apparatus can be provided without reducing the lifetime of the light source lamp.

A method of illuminating a light valve using a light source with modulated intensity to improve light throughput and color balance while minimizing loss of color resolution. A light valve is provided that includes a light input, a light output and a spatial light modulator including an array of pixels. The spatial light modulator is illuminated through the light input with light generated by a light source having a nominal lamp power dissipation level. Image data is provided and the array of pixels is configured based on the image data during a display period so that the image data is represented in light from the light source received at the light output. During a portion of the display period, the intensity of the light generated by the light source is increased to a high level above the nominal lamp power dissipation. During another portion of the display period, the intensity of the light generated by the light source is decreased to a low level below the nominal lamp power dissipation level. The average lamp power dissipation level over the display period is maintained at a level that does not exceed the nominal lamp power dissipation level. The light valve provided may additionally include a color sequencer for sequentially selecting one of a first, a second, and a third colorband of light that may reach the light output. Alternatively, the light valve provided may include a first, a second, and a third spatial light modulator and a color separator for directing a first, a second, and a third colorband of light from light received at the light input to the first, the second, and the third spatial light modulator, respectively. The light valve provided may also include a first, second,, and third shutter between the color separator and the first, second, and third spatial light modulator, respectively.

A thin film transistor liquid crystal display (TFT-LCD) capable of adjusting its light source utilizes at least one thin film transistor (TFT) disposed in a peripheral region of a bottom substrate as a photo sensor for detecting ambient illumination. Then, a light source modulator can enhance, weaken, open or close the light source of the TFT-LCD to an optimal brightness level that depends on the ambient illumination spontaneously.