Matsushita Electric Industrial Co., Ltd.

Wataru Machidori

Katsuyuki Arimoto

Taro Funamoto

Takahiro Kobayashi

Yoshihito Ota

Kazuo Inoue

Katsuhiko Kumagawa

Ichiro Sato

Yoshihito Ohta

Yasuhiro Kumamoto

Tetsuo Kariya

An image display apparatus and method provided for visually improving a sense of contrast by adjusting contrast and a light source to have a correlation. A characteristics detection part detects MAX, MIN, and APL (average) of an input signal. A control data generation part calculates Gain for amplifying a difference between MAX and MIN to a width of a dynamic range and Offset indicating the DC level to be shifted so that the input video signal amplified by Gain falls within the output dynamic range of a DC level adjustment part. A signal amplitude adjustment part amplifies the input video signal with reference to APL and in accordance with Gain. The DC level adjustment part shifts the DC level of the amplified input video signal in accordance with a value of Offset. A light source control part controls a light source so that a visual brightness level on a screen is equal to a brightness level of the input video signal.

Image display apparatus and image display method

An image display apparatus and method are provided for visually improving a sense of contrast by adjusting contrast and a light source to have a correlation. A characteristics detection part detects MAX, MIN, and APL (average) of an input signal. A control data generation part calculates Gain for amplifying a difference between MAX and MIN to a width of a dynamic range and Offset indicating the DC level to be shifted so that the input video signal amplified by Gain falls within the output dynamic range of a DC level adjustment part. A signal amplitude adjustment part amplifies the input video signal with reference to APL and in accordance with Gain. The DC level adjustment part shifts the DC level of the amplified input video signal in accordance with a value of Offset. A light source control part controls a light source so that a visual brightness level on a screen is equal to a brightness level of the input video signal.

When displaying moving images by using liquid crystal panels and others, a problem exists in that tail streaks occur, and image degradation is resultantly caused. To solve this problem, an echo suppression circuit divides a video signal into a pair composed of two successive frames for comparison between these two frames in signal level for the purpose of suppressing an echo phenomenon occurring when a liquid crystal panel displays video signals including moving images. If these two frames are not the same in signal level, the signal is accordingly corrected so as to equalize the signal level of these frames. Based on the video signals and others corrected by the echo suppression circuit, a controller operates the liquid crystal panel with AC drive through a source driver and a gate driver. As such, the drive voltage used to operate the liquid crystal panel with AC drive is adjusted so as to be balanced between positive and negative. In this manner, the tail streaks are prevented when displaying moving images.

A liquid crystal display apparatus that uses a backlight for display includes a video signal time compression circuit for compressing a video signal in the time axis direction and outputting the time-compressed video signal, an LCD controller for driving a liquid crystal panel based on the time-compressed video signal, and a source driver and a gate driver. The liquid crystal display apparatus also includes a motion detection circuit for detecting the amount of motion of a display image based on the video signal, a PWM modulation pulse generation circuit for generating modulation pulses different in frequency according to the detection result from the motion detection circuit, and an inverter for lighting up the backlight based on the modulation pulses, to thereby enable reduction of image contour blurring in a moving image and reduction of flicker in a still image.

Image display apparatus and method

Provided are an image display apparatus and method capable of visually improving a sense of contrast by adjusting contrast and a light source to have correlation. A characteristics detection part detects MAX, MIN, and APL of an input signal. A control data generation part calculates Gain for amplifying a difference between MAX and MIN to a width of a dynamic range and Offset indicating the DC level to be shifted so that the input video signal amplified by Gain falls with in the output dynamic range of a DC level adjustment part B. A signal amplitude adjustment part A amplifies the input video signal with reference to APL and in accordance with Gain. The DC level adjustment part B shifts the DC level of the amplified input video signal in accordance with a value of Offset. A light source control part controls a light source so that a visual brightness level on a screen is equal to a brightness level of the input video signal.

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Amagasaki, Japan

Wataru Machidori