Liquid crystal display and liquid crystal television

摘要

The present invention provides a liquid crystal display capable of making the variations and the oblique lines, which are caused on the screen in the liquid crystal display using the TN liquid crystal panel, less visible. The liquid crystal display includes a video signal reception section adapted to receive a video signal, a signal input detection section adapted to detect presence or absence of the video signal, a luminance control section adapted to control the luminance of the backlight, and a control section adapted to instruct the luminance control section to reduce the luminance of the backlight as a predetermined amount in the case in which the signal input detection section fails to detect the video signal.

主权项

1. A liquid crystal display, comprising:
a Twisted Nematic (TN) liquid crystal panel and a backlight for emitting light from behind the liquid crystal panel, and varying transmission of each pixel in the liquid crystal panel based on a video signal, thereby displaying an image with the transmitted light that is transmitted through each pixel of the liquid crystal panel; a video signal reception section for receiving the video signal contained in a Transport Stream of digital television broadcasting signal; a signal input detection section for detecting the video signal based on a table which records channel numbers contained in the Transport stream; a luminance control section for controlling the luminance of the backlight with Pulse Width Modulation (PWM) control for varying a duty ratio of a pulse signal; a control section for outputting a control signal to the luminance control section so that the luminance control section varies the duty ratio of the pulse signal; a table for storing a luminance control range that has a range of value which can be set by an operation input; wherein when the video signal is detected by the signal input detection section, the control section outputs the control signal so that the luminance control section controls the luminance of the backlight based on the luminance control range and when the video signal is not detected by the signal input detection section, the control section outputs the control signal so that the luminance control section reduces the value of the luminance of the backlight lower than the minimum value of the luminance control range.